Regenerate configure after changing configure.ac in GH-6987. (GH-7344)

Author: serhiy-storchaka

configure

@@ -3000,7 +3000,7 @@ if test "${enable_universalsdk+set}" = set; then :
   enableval=$enable_universalsdk;
 	case $enableval in
 	yes)
-		# Locate the best usable SDK, see Mac/README.txt for more
+		# Locate the best usable SDK, see Mac/README for more
 		# information
 		enableval="`/usr/bin/xcodebuild -version -sdk macosx Path 2>/dev/null`"
 		if ! ( echo $enableval | grep -E '\.sdk' 1>/dev/null )
@@ -3455,7 +3455,7 @@ fi
 if test "$ac_sys_system" = "Darwin"
 then
 	# Compiler selection on MacOSX is more complicated than
-	# AC_PROG_CC can handle, see Mac/README.txt for more
+	# AC_PROG_CC can handle, see Mac/README for more
 	# information
 	if test -z "${CC}"
 	then