Handle alphanumeric characters in matching GUC names

The check for whether all GUCs are present in the sample config
file used the POSIX character class :alpha: which corresponds to
alphabet and not alphanumeric. Since GUC names can contain digits
as well we need to use the :alnum: character class instead.

Author: Daniel Gustafsson <[email protected]>
Discussion: https://postgr.es/m/[email protected]

Author: danielgustafsson

src/test/modules/test_misc/t/003_check_guc.pl

@@ -56,7 +56,7 @@
 	# file.
 	# - Valid configuration options are followed immediately by " = ",
 	# with one space before and after the equal sign.
-	if ($line =~ m/^#?([_[:alpha:]]+) = .*/)
+	if ($line =~ m/^#?([_[:alnum:]]+) = .*/)
 	{
 		# Lower-case conversion matters for some of the GUCs.
 		my $param_name = lc($1);