Fix postgresql::default() return value for unknown parameters

When calling `postgresql::default()` with a name that has no corresponding
parameter, the function returns the string
"postgresql::globals::<parameter-name>" which is probably not intended
given the comment above the code.

The usage of pick seems to indicate that an exception should be raised
when a parameter is not found in `params` nor `globals.pp`, so adjust
the code accordingly.

Author: smortex

functions/default.pp

@@ -10,6 +10,5 @@ function postgresql::default(
 
   #search for the variable name in params first
   #then fall back to globals if not found
-  pick( getvar("postgresql::params::${parameter_name}"),
-  "postgresql::globals::${parameter_name}")
+  pick(getvar("postgresql::params::${parameter_name}"), getvar("postgresql::globals::${parameter_name}"))
 }