ensure gdbserver allows a single connection and warn users if debugger already is running

package.json

@@ -102,7 +102,7 @@
         "c9.ide.recentfiles": "#7c099abf40",
         "c9.ide.remote": "#301d2ab519",
         "c9.ide.processlist": "#bc11818bb5",
-        "c9.ide.run": "#db7ca8eb81",
+        "c9.ide.run": "#6c32e5de36",
         "c9.ide.run.build": "#ad45874c88",
         "c9.ide.run.debug.xdebug": "#3b1520f83d",
         "c9.ide.save": "#cc613b6ead",