console.log shouldn't throw warning if metro isn't running

Summary: When metro is not running, D15559151 caused infinite exceptions (fetch threw an error if it couldn't connect to localhost:8081) which affected UI. Swallow those errors and everything works well, with or without metro.

Reviewed By: yungsters

Differential Revision: D15588623

fbshipit-source-id: d170ea82478545836a7a22a228196c9778e93ef0

Libraries/Core/Devtools/logToConsole.js

@@ -27,6 +27,13 @@ function logToConsole(
   fetch(getDevServer().url + 'log-to-console', {
     method: 'POST',
     body,
+  }).catch(e => {
+    // ...Oh well!
+    // If metro is running, logs should be sent to metro.
+    // If metro is NOT running, this will throw an exception every time... and
+    //  those exceptions will be caught and logged, which will throw another
+    //  exception, etc, causing infinite exception loop which affects UI perf.
+    // If we swallow silently here, that won't happen.
   });
 }