YAHFA: add global ref to backup method

(cherry picked from commit PAGalaxyLab/YAHFA@debcd063)

edxp-core/src/main/cpp/external/yahfa/src/HookMain.c

@@ -319,6 +319,7 @@ jboolean Java_lab_galaxy_yahfa_HookMain_backupAndHookNative(JNIEnv *env, jclass
     )) {
         (*env)->NewGlobalRef(env,
                              hook); // keep a global ref so that the hook method would not be GCed
+        if (backup) (*env)->NewGlobalRef(env, backup);
         return JNI_TRUE;
     } else {
         return JNI_FALSE;