Do not auto-add console logger when one already exists

Author: reidmorrison

lib/rails_semantic_logger/engine.rb

@@ -221,7 +221,8 @@ class Engine < ::Rails::Engine
       console do |_app|
         # Don't use a background thread for logging
         SemanticLogger.sync!
-        if config.rails_semantic_logger.console_logger
+        # Add a stderr logger when running inside a Rails console unless one has already been added.
+        if config.rails_semantic_logger.console_logger && !SemanticLogger::Logger.processor.appenders.console_output?
           SemanticLogger.add_appender(io: STDERR, formatter: :color)
         end