Lws now strips out http headers releated to h2, ws and unusual headers
based on cmake config settings for those features... it saves some heap
for the ah and reduces the table size in .rodata.

It's possible code might have some external dependency on the original
header indexes, but, eg, you don't enable h2 so those indexes are
optimized with the h2 ones taken out.

This introduces a cmake option "LWS_HTTP_HEADERS_ALL", default-OFF, that
defeats the header table optimization for compatibility with older
versions in the case the client software can't be adapted to use the
lws-exported matching header enums.

You probably don't need this.