Fix bit-shifting of websockets frame fields that would yield wrong opcodes

when the FIN bit was set.  Results in PING not being recognized
by mod_lua.  PR57524

Submitted By: Edward Lu
Committed By: covener



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1657256 13f79535-47bb-0310-9956-ffa450edef68