bluez5 - dont have timer repeat that we are just ablout to add again

we call ping_schedule anyway. we want this as timeout may vary.. then
dont return true to repeat the timer we have... saves having loooots
of timers going off.

@fix

src/modules/bluez5/bz_obj.c

@@ -683,7 +683,7 @@ cb_ping_timer(void *data)
    o->ping_block = EINA_FALSE;
    ping_do(o);
    ping_schedule(o);
-   return EINA_TRUE;
+   return EINA_FALSE;
 }
 
 void