[ReactNative] Suggest un-pausing debugger when there are issues

Summary:
@public
The most common problem I've noticed is that the debugger is paused, so we
shouldn't ask the user if Chrome is open, because it usually is.

Test Plan: Try to reload with debugger paused, see new error message.

Libraries/RCTWebSocketDebugger/RCTWebSocketExecutor.m

@@ -66,7 +66,8 @@ typedef void (^WSMessageCallback)(NSError *error, NSDictionary *reply);
       retries--;
     }
     if (!runtimeIsReady) {
-      RCTLogError(@"Runtime is not ready. Do you have Chrome open?");
+      RCTLogError(@"Runtime is not ready. Make sure Chrome is running and not "
+        "paused on a breakpoint or exception and try reloading again.");
       [self invalidate];
       return nil;
     }