Update flask_admin/contrib/peeweemodel/tools.py

Peewee allow to create PrimaryKeys like IntegerField(primary_key=True)

flask_admin/contrib/peeweemodel/tools.py

@@ -3,7 +3,7 @@ from peewee import PrimaryKeyField
 
 def get_primary_key(model):
     for n, f in model._meta.get_sorted_fields():
-        if type(f) == PrimaryKeyField:
+        if type(f) == PrimaryKeyField or f.primary_key:
             return n