fix route with param name generation

Author: krasnoukhov

lib/rspec_api_documentation/writers/open_api_writer.rb

@@ -302,7 +302,7 @@ def requests
       end
 
       def route
-        super.gsub(/:(?<parameter>[^\/]+)/, '{\k<parameter>}')
+        super.gsub(/:(\w+)/, '{\1}')
       end
     end
   end