web_ws.__all__ fix: add missing WSMsgType
web_ws.__all__ fix: add missing WSMsgType

alex-eri/aiohttp-1,panda73111/aiohttp,esaezgil/aiohttp,panda73111/aiohttp,AraHaanOrg/aiohttp,Eyepea/aiohttp,singulared/aiohttp,moden-py/aiohttp,KeepSafe/aiohttp,moden-py/aiohttp,hellysmile/aiohttp,rutsky/aiohttp,arthurdarcet/aiohttp,arthurdarcet/aiohttp,juliatem/aiohttp,esaezgil/aiohttp,z2v/aiohttp,arthurdarcet/aiohttp,rutsky/aiohttp,z2v/aiohttp,alex-eri/aiohttp-1,juliatem/aiohttp,moden-py/aiohttp,playpauseandstop/aiohttp,esaezgil/aiohttp,panda73111/aiohttp,singulared/aiohttp,pfreixes/aiohttp,KeepSafe/aiohttp,z2v/aiohttp,AraHaanOrg/aiohttp,KeepSafe/aiohttp,singulared/aiohttp,pfreixes/aiohttp,rutsky/aiohttp,alex-eri/aiohttp-1,hellysmile/aiohttp