Windows: Add missing quotes in build file
All invokations of $(PERL) need to be quoted, in case it contains
spaces.  That was forgotten in one spot.
Fixes
@@ -539,7 +539,7 @@ reconfigure reconf:
$args{generator}->[1] || platform->dsoname($args{product});
return <<"EOF";
$target: $args{generator}->[0] $deps $mkdef
- \$(PERL) $mkdef$ord_ver --ordinals $args{generator}->[0] --name $ord_name --OS windows > $target
+ "\$(PERL)" $mkdef$ord_ver --ordinals $args{generator}->[0] --name $ord_name --OS windows > $target
EOF
} elsif (!platform->isasm($args{src})) {
my $target = $args{src};
