Lower connection timeout from 12 to 7 seconds

This allows for 3 connection attempts in 25 seconds background time.

Monal/Classes/xmpp.m

@@ -50,7 +50,7 @@
 @import WebRTC;
 
 #define STATE_VERSION 9
-#define CONNECT_TIMEOUT 12.0
+#define CONNECT_TIMEOUT 7.0
 #define IQ_TIMEOUT 60.0
 NSString* const kQueueID = @"queueID";
 NSString* const kStanza = @"stanza";