Revert "temp: add lms_user_id to django admin (#322)"

This reverts commit b67d678.

commerce_coordinator/apps/core/admin.py

@@ -12,7 +12,7 @@ class CustomUserAdmin(UserAdmin):
     """ Admin configuration for the custom User model. """
     list_display = ('username', 'email', 'full_name', 'first_name', 'last_name', 'is_staff', 'lms_user_id')
     fieldsets = (
-        (None, {'fields': ('username', 'password', 'lms_user_id')}),
+        (None, {'fields': ('username', 'password')}),
         (_('Personal info'), {'fields': ('full_name', 'first_name', 'last_name', 'email')}),
         (_('Permissions'), {'fields': ('is_active', 'is_staff', 'is_superuser',
                                        'groups', 'user_permissions')}),