Remove duplication

logging_config.js

 /* eslint-disable no-unused-vars, no-var */
+
 // Logging configuration
-// XXX When making any changes to this file make sure to also update it's React
-// version at ./react/features/base/logging/reducer.js !!!
 var loggingConfig = {
     // default log level for the app and lib-jitsi-meet
     defaultLogLevel: 'trace',
 
     // The following are too verbose in their logging with the
     // {@link #defaultLogLevel}:
+    'modules/RTC/TraceablePeerConnection.js': 'info',
     'modules/statistics/CallStats.js': 'info',
-    'modules/xmpp/strophe.util.js': 'log',
-    'modules/RTC/TraceablePeerConnection.js': 'info'
+    'modules/xmpp/strophe.util.js': 'log'
 };
 
 /* eslint-enable no-unused-vars, no-var */
+
+// XXX Web/React server-includes logging_config.js into index.html.
+// Mobile/react-native requires it in react/features/base/logging. For the
+// purposes of the latter, (try to) export loggingConfig. The following
+// detection of a module system is inspired by webpack.
+typeof module === 'object'
+    && typeof exports === 'object'
+    && (module.exports = loggingConfig);

react/features/base/logging/reducer.js

 /**
  * The default/initial redux state of the feature base/logging.
  *
- * XXX When making any changes to the DEFAULT_STATE make sure to also update
- * logging_config.js file located in the root directory of this project !!!
- *
  * @type {{
  *     config: Object
  * }}
  */
 const DEFAULT_STATE = {
-    config: {
-        defaultLogLevel: 'trace',
-
-        // The following are too verbose in their logging with the
-        // {@link #defaultLogLevel}:
-        'modules/statistics/CallStats.js': 'info',
-        'modules/xmpp/strophe.util.js': 'log',
-        'modules/RTC/TraceablePeerConnection.js': 'info'
-    }
+    config: require('../../../../logging_config.js')
 };
 
 ReducerRegistry.register(