Allow empty string for setting value

Some PHP features are enabled by default and can be disabled by using an
empty string as a setting value, e.g. user_ini.filename.  The code
currently require a non-empty string, making it impossible to disable
such a feature.

Allow an empty string as the value of a setting.

Author: smortex

manifests/config/setting.pp

@@ -20,7 +20,7 @@
 #
 define php::config::setting (
   String[1] $key,
-  Variant[Integer, String[1]] $value,
+  Variant[Integer, String] $value,
   Stdlib::Absolutepath $file,
 ) {
   assert_private()