perlPackages: Regenerate metadata (phase 1)

This is required because my parser/generator is very primitive :/

pkgs/development/perl-modules/MNI/default.nix

@@ -15,9 +15,10 @@ buildPerlPackage {
 
   doCheck = false;  # TODO: almost all tests fail ... is this a real problem?
 
-  meta = with lib; {
+  meta = {
+    description = "MNI MINC perllib (not used much anymore)";
     homepage = "https://github.com/BIC-MNI/mni-perllib";
-    license = with licenses; [ artistic1 gpl1Plus ];
-    maintainers = with maintainers; [ bcdarwin ];
+    license = with lib.licenses; [ artistic1 gpl1Plus ];
+    maintainers = with lib.maintainers; [ bcdarwin ];
   };
 }

pkgs/development/perl-modules/Percona-Toolkit/default.nix

@@ -24,9 +24,9 @@ buildPerlPackage rec {
   '';
 
   meta = with lib; {
-    description = "Collection of advanced command-line tools to perform a variety of MySQL and system tasks.";
+    description = "Collection of advanced command-line tools to perform a variety of MySQL and system tasks";
     homepage = "https://www.percona.com/software/database-tools/percona-toolkit";
-    license = with licenses; [ gpl2 ];
+    license = with licenses; [ gpl2Only ];
     maintainers = with maintainers; [ izorkin ];
   };
 }

pkgs/development/perl-modules/Po4a/default.nix

@@ -30,8 +30,8 @@ buildPerlPackage rec {
     done
   '';
   meta = {
-    homepage = "https://po4a.org/";
     description = "Tools for helping translation of documentation";
-    license = lib.licenses.gpl2;
+    homepage = "https://po4a.org";
+    license = with lib.licenses; [ gpl2Only ];
   };
 }

pkgs/development/perl-modules/strip-nondeterminism/default.nix

@@ -34,7 +34,7 @@ buildPerlPackage rec {
   meta = with lib; {
     description = "A Perl module for stripping bits of non-deterministic information";
     homepage = "https://reproducible-builds.org/";
-    license = licenses.gpl3;
+    license = licenses.gpl3Only;
     maintainers = with maintainers; [ pSub ];
   };
 }