Added null check for mListener in SkyHook.java

closes #66

Signed-off-by: Ricky Barrette <rickbarrette@gmail.com>

LocationLib/src/com/TwentyCodes/android/SkyHook/SkyHook.java

@@ -298,6 +298,7 @@ public class SkyHook implements GeoPointLocationListener{
 
 	@Override
 	public void onFirstFix(boolean firstFix) {
+		if(mListener != null)
 			mListener.onFirstFix(firstFix);
 	}
 }