Illegal Argument Exception: Illegal URL

[CamposErik]

Describe the bug
When I try to call the GLPI class it gives this error.

    void start(String url) {

        OkHttpClient okHttpClient = new OkHttpClient().newBuilder()
                .connectTimeout(CONNECT_TIMEOUT, TimeUnit.SECONDS)
                .readTimeout(READ_TIMEOUT, TimeUnit.SECONDS)
                .writeTimeout(WRITE_TIMEOUT, TimeUnit.SECONDS)
                .build();

        retrofit = new Retrofit.Builder()
                .baseUrl(url)
                .client(okHttpClient)
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .build();

    }
}

2018-12-21 11:01:24.027 12537-12537/? E/AndroidRuntime: FATAL EXCEPTION: main
    Process: org.flyve.admin.dashboard, PID: 12537
    java.lang.RuntimeException: Unable to start activity ComponentInfo{org.flyve.admin.dashboard/org.flyve.admin.dashboard.login.LoginActivity}: java.lang.IllegalArgumentException: Illegal URL: 
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3194)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3302)
        at android.app.ActivityThread.-wrap12(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1891)
        at android.os.Handler.dispatchMessage(Handler.java:108)
        at android.os.Looper.loop(Looper.java:166)
        at android.app.ActivityThread.main(ActivityThread.java:7425)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:245)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:921)
     Caused by: java.lang.IllegalArgumentException: Illegal URL: 
        at retrofit2.Retrofit$Builder.baseUrl(Retrofit.java:454)
        at org.glpi.api.ServiceGenerator.start(ServiceGenerator.java:58)
        at org.glpi.api.GLPI.<init>(GLPI.java:79)
        at org.flyve.admin.dashboard.login.LoginActivity.onCreate(LoginActivity.java:67)
        at android.app.Activity.performCreate(Activity.java:7372)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1218)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3147)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3302) 
        at android.app.ActivityThread.-wrap12(Unknown Source:0) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1891) 
        at android.os.Handler.dispatchMessage(Handler.java:108) 
        at android.os.Looper.loop(Looper.java:166) 
        at android.app.ActivityThread.main(ActivityThread.java:7425) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:245) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:921) 
2018-12-21 11:01:24.054 751-2461/? E/iMonitor: FaultDetect: DUMPTOOL_PRINTF return.

final GLPI glpi = new GLPI(MainActivity.this, BuildConfig.GLPI_URL);