Remove outdated note about DEV mode in logs (#3472)

This log was removed via facebook/react-native@1f25d3c, and referencing it can be confusing.

Author: bent0b0x

docs/profiling.md

@@ -7,7 +7,7 @@ Profiling is the process of analyzing an app's performance, resource usage, and
 
 For iOS, Instruments is an invaluable tool, and on Android you should learn to use the [Android Studio Profiler](profiling.md#profiling-android-ui-performance-with-system-tracing).
 
-But first, [**make sure that Development Mode is OFF!**](performance.md#running-in-development-mode-devtrue) You should see `__DEV__ === false, development-level warning are OFF, performance optimizations are ON` in your application logs.
+But first, [**make sure that Development Mode is OFF!**](performance.md#running-in-development-mode-devtrue).
 
 ## Profiling Android UI Performance with System Tracing