htop: verify htoprc contents for example settings test

Fix ending the generated htoprc with a newline.

modules/programs/htop.nix

@@ -146,7 +146,8 @@ in {
     home.packages = [ pkgs.htop ];
 
     xdg.configFile."htop/htoprc" = mkIf (cfg.settings != { }) {
-      text = concatStringsSep "\n" (mapAttrsToList formatOption cfg.settings);
+      text = concatStringsSep "\n" (mapAttrsToList formatOption cfg.settings)
+        + "\n";
     };
   };
 }

tests/modules/programs/htop/example-htoprc.txt

@@ -0,0 +1,11 @@
+color_scheme=6
+cpu_count_from_one=0
+delay=15
+fields=0 48 17 18 38 39 40 2 46 47 49 1
+highlight_base_name=1
+highlight_megabytes=1
+highlight_threads=1
+left_meter_modes=1 1 1 2
+left_meters=AllCPUs2 Memory Swap Zram
+right_meter_modes=2 2 2 2
+right_meters=Tasks LoadAverage Uptime Systemd

tests/modules/programs/htop/example-settings.nix

@@ -37,7 +37,9 @@ with lib;
         ]);
 
     nmt.script = ''
-      assertFileExists home-files/.config/htop/htoprc
+      htoprc=home-files/.config/htop/htoprc
+      assertFileExists $htoprc
+      assertFileContent $htoprc ${./example-htoprc.txt}
     '';
   };
 }