Need to preserve --with-pcre value if not a path ref

APACHE_HELP_STRING(--with-pcre=PATH,Use external PCRE library))

if test "x$with_pcre" = "x" || test "$with_pcre" = "yes"; then

  with_pcre="$PATH"

else

else if which $with_pcre 2>/dev/null; then :; else

  with_pcre="$with_pcre/bin:$with_pcre"

fi

fi

AC_CHECK_TARGET_TOOLS(PCRE_CONFIG, [pcre2-config pcre-config],

                      [`which $with_pcre 2>/dev/null`], $with_pcre)