use tr instead of gsub when possible

actionview/lib/action_view/template.rb

@@ -317,7 +317,7 @@ def locals_code #:nodoc:
       end
 
       def method_name #:nodoc:
-        @method_name ||= "_#{identifier_method_name}__#{@identifier.hash}_#{__id__}".gsub('-', "_")
+        @method_name ||= "_#{identifier_method_name}__#{@identifier.hash}_#{__id__}".tr('-', "_")
       end
 
       def identifier_method_name #:nodoc:

activerecord/lib/active_record/connection_adapters/connection_specification.rb

@@ -33,7 +33,7 @@ class ConnectionUrlResolver # :nodoc:
         def initialize(url)
           raise "Database URL cannot be empty" if url.blank?
           @uri     = uri_parser.parse(url)
-          @adapter = @uri.scheme.gsub('-', '_')
+          @adapter = @uri.scheme.tr('-', '_')
           @adapter = "postgresql" if @adapter == "postgres"
 
           if @uri.opaque