Moving stun_prober target from webrtc/p2p to webrtc/examples

BUG=webrtc:6440
NOTRY=True

Review-Url: https://codereview.webrtc.org/2460343002
Cr-Commit-Position: refs/heads/master@{#14869}
diff --git a/webrtc/webrtc_examples.gyp b/webrtc/webrtc_examples.gyp
index 6627c31..38fbd35 100755
--- a/webrtc/webrtc_examples.gyp
+++ b/webrtc/webrtc_examples.gyp
@@ -465,6 +465,17 @@
             '../build/android/test_runner.gypi',
           ],
         },
+        {
+          'target_name': 'stun_prober',
+          'type': 'executable',
+          'dependencies': [
+            'p2p:libstunprober',
+            'p2p:rtc_p2p'
+          ],
+          'sources': [
+            'examples/stunprober/main.cc',
+          ],
+        },
       ],  # targets
     }],  # OS=="android"
   ],