fix crash when request an undefined action

here log:
16:05:20.268 [error] Error in controller error {badmatch,{test_test_controller,{simple_bridge_request_wrapper,mochiweb_request_bridge,{mochicow_request,#Port<0.24739>,'GET',"/test/index2",'HTTP/1.1',{8,{"host",{"host","localhost:8001"},{"accept",{"accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"},nil,{"accept-language",{"accept-language","en-US,en;q=0.5"},{"accept-encoding",{"accept-encoding","gzip, deflate"},nil,nil},{"cookie",{"cookie","_tracksapp_session=MEcvczhiY1ZWbGxxY3dMcnEyajNwS3ZzTG5NTFFkSmhLZ3JjU1lzRmlvTEkyTnphS3NuTXZCMU9jN081ME9JdXZSYUNVcXJkVlpoRG5TTjRCKzNmNnNvRVViZGxuV1dQMzJUYkZvZmk0NzE5RFMyZlk4andEcENaK0k2bXRVT01oYmZRMXF6R3RhcXcvdWEyU0dhMmVRPT0tLTJwdEtuOTF1QmZ6UUJXU1RRNEFqdEE9PQ%3D%3D--b1b5b0881c04c1bc4ffbd4734caf058ed2bb0138; _boss_session=382fc636e18869104afc86fb3f78fb0c1166a474"},{"connection",{"connection","keep-alive"},{"cache-control",{"cache-control","max-age=0"},nil,nil},nil},nil}}},{"user-agent",{"user-agent","Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:31.0) Gecko/20100101 Firefox/31.0"},nil,nil}}},<<>>},false,[],[],none},"0e5e85f3db7732b8a587c8a7b692f9b6bf24b418"}} [{boss_controller_adapter_pmod,action,2,[{file,"src/boss/controller_adapters/boss_controller_adapter_pmod.erl"},{line,99}]},{boss_web_controller,call_controller_action,3,[{file,"src/boss/boss_web_controller.erl"},{line,316}]},{boss_web_controller,apply_action,4,[{file,"src/boss/boss_web_controller.erl"},{line,308}]},{boss_web_controller,execute_action_inner,9,[{file,"src/boss/boss_web_controller.erl"},{line,287}]},{boss_web_controller_handle_request,process_dynamic_request,5,[{file,"src/boss/boss_web_controller_handle_request.erl"},{line,254}]},{boss_web_controller_handle_request,process_request,5,[{file,"src/boss/boss_web_controller_handle_request.erl"},{line,240}]},{boss_web_controller_handle_request,set_timer,8,[{file,"src/boss/boss_web_controller_handle_request.erl"},{line,160}]},{boss_web_controller_handle_request,build_dynamic_response,5,[{file,"src/boss/boss_web_controller_handle_request.erl"},{line,129}]}]