Reverting change adding /etc/mysql support, as it breaks some installs.

mysys/default.c

@@ -978,11 +978,10 @@ static uint my_get_system_windows_directory(char *buffer, uint size)
 
   Everywhere else, this is:
     1. /etc/
-    2. /etc/mysql/
-    3. getenv(DEFAULT_HOME_ENV)
-    4. ""
-    5. "~/"
-    6. --sysconfdir=<path>
+    2. getenv(DEFAULT_HOME_ENV)
+    3. ""
+    4. "~/"
+    5. --sysconfdir=<path>
 
  */
 
@@ -1008,7 +1007,6 @@ static void init_default_directories()
     *ptr++= env;
 #endif
   *ptr++= "/etc/";
-  *ptr++= "/etc/mysql/";
 #endif
   if ((env= getenv(STRINGIFY_ARG(DEFAULT_HOME_ENV))))
     *ptr++= env;