Sync --enable-mysqlnd-compression-support option (php#12006)

This syncs the style of the --enable-mysqlnd-compression-support option
name, otherwise in Autoconf both --enable-foo_bar and --enable-foo-bar
work.

Also the configure output message is synced to match the check
information.

Author: petk

ext/mysqlnd/config9.m4

@@ -6,8 +6,8 @@ PHP_ARG_ENABLE([mysqlnd],
   [no],
   [yes])
 
-PHP_ARG_ENABLE([mysqlnd_compression_support],
-  [whether to disable compressed protocol support in mysqlnd],
+PHP_ARG_ENABLE([mysqlnd-compression-support],
+  [whether to enable compressed protocol support in mysqlnd],
   [AS_HELP_STRING([--disable-mysqlnd-compression-support],
     [Disable support for the MySQL compressed protocol in mysqlnd])],
   [yes],