Fixed bug #3512076 by placing #include "proto_x11.h" inside a USE_X11 ifdef block

git-svn-id: svn+ssh://svn.code.sf.net/p/spacenav/code/trunk/spacenavd@142 ef983eb1-d774-4af8-acfd-baaf7b16a646

src/event.c

@@ -21,11 +21,11 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <stdlib.h>
 #include "event.h"
 #include "client.h"
-#include "proto_x11.h"
 #include "proto_unix.h"
 #include "spnavd.h"
 
 #ifdef USE_X11
+#include "proto_x11.h"
 #include "kbemu.h"
 #endif