Fix for Visual C++ compilation

[marcstern]

Visual C++ doesn't accept that code from cfg/cmds.c:

     AP_INIT_TAKE1(
         OIDCCacheType,
         oidc_cmd_cache_type_set,
         NULL,
         RSRC_CONF,
         "cache backend must be one of ['shm'|"
 #ifdef USE_MEMCACHE
         "'memcache'|"
 #endif
 #ifdef USE_LIBHIREDIS
         "'redis'|"
 #endif
         "'file']."),

We have to modify the #ifdef outside the macro, like this:

 #ifdef USE_MEMCACHE
 # define CACHETYPEINFO_MEMCACHE "'memcache'|"
 #else
 # define CACHETYPEINFO_MEMCACHE
 #endif
 #ifdef USE_LIBHIREDIS
 # define CACHETYPEINFO_REDIS "'redis'|"
 #else
 # define CACHETYPEINFO_REDIS
 #endif
 #define CACHETYPEINFO "cache backend must be one of ['shm'|" CACHETYPEINFO_MEMCACHE CACHETYPEINFO_REDIS "'file']."
     OIDC_CFG_CMD(
         AP_INIT_TAKE1,
         OIDCCacheType,
         cache_type,
         CACHETYPEINFO),