Avoid possible infinite recursion

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/user/configs/console/git/default.nix

@@ -1,5 +1,5 @@
 {
-  user ? throw "user argument is required",
+  username ? throw "username argument is required",
 }:
 {
   config,
@@ -8,15 +8,16 @@
   ...
 }:
 let
-  hmConfig = config.home-manager.users.${user.name};
+  userConfig = config.users.users.${username};
+  hmConfig = config.home-manager.users.${username};
 in
 {
-  home-manager.users.${user.name} = {
+  home-manager.users.${username} = {
     programs.git = {
       enable = true;
       lfs.enable = true;
-      userName = user.fullName;
-      userEmail = user.email;
+      userName = userConfig.fullName;
+      userEmail = userConfig.email;
 
       signing = {
         signByDefault = true;