remove more nil checks

activerecord/lib/active_record/associations/belongs_to_association.rb

@@ -8,17 +8,16 @@ def handle_dependency
       end
 
       def replace(record)
-        raise_on_type_mismatch!(record) if record
-
-        update_counters(record)
         if record
+          raise_on_type_mismatch!(record)
+          update_counters(record)
           replace_keys(record)
+          set_inverse_instance(record)
+          @updated = true
         else
+          update_counters(record)
           remove_keys
         end
-        set_inverse_instance(record) if record
-
-        @updated = true if record
 
         self.target = record
       end