This reduces the number of moving parts in ABI compatibility checks.
Additionally, it also allows to use OpenSSL in FIPS mode while still
using md5 for non-security tasks.
*) Change: now the ngx_http_charset_module works for subrequests, if
the response has no "Content-Type" header line.
*) Bugfix: if the "proxy_pass" directive has no URI part, then the
"proxy_redirect default" directive add the unnecessary slash in
start of the rewritten redirect.
*) Bugfix: the internal redirect always transform client's HTTP method
to GET, now the transformation is made for the "X-Accel-Redirect"
redirects only and if the method is not HEAD; the bug had appeared
in 0.3.42.
*) Bugfix: the ngx_http_perl_module could not be built, if the perl was
built with the threads support; the bug had appeared in 0.3.46.
