Setting -Wstrict-prototypes in combination with -Werror leads to compiler errors during configure checks (autoconf generates incomplete prototypes).
Adding -Wno-error=strict-prototypes lets the compiler tolerate those.
Possible future enhancement: remember such "configure time only" flags and remove them from CFLAGS before generating our build time files (Makefile, config_vars.mk etc.), so that the full -Werror is in place during building.
Follow up to r1812263.
As suggested by Joe, add --maintainer/debugger-mode's CFLAGS in NOTEST_CFLAGS to avoid interractions with autoconf's AC_LANG_PROGRAM.
APACHE_ADD_GCC_CFLAG now also forces -Wno-strict-prototypes for -Werror to work despite AC_LANG_PROGRAM generating this warning by itself.
Submitted by: rjung, ylavic Reviewed by: ylavic, rjung, jim