Fix inferior deletion

Author: rohanrhu

debug_server.py

@@ -323,7 +323,8 @@ def _mt():
     def gdb_on_exited__mT(self, event):
         response = {}
 
-        del api.globalvars.inferior_run_times[event.inferior.num]
+        try: del api.globalvars.inferior_run_times[event.inferior.num]
+        except: pass
 
         api.globalvars.debugFlags.set(api.flags.AtomicDebugFlags.SELECTED_FRAMES, {})