Fixes in imagefield and jsonfield

paramecio2/libraries/db/extrafields/jsonfield.py

@@ -72,6 +72,7 @@ class JsonValueField(PhangoField):
         super().__init__(name, required)
     
         self.error_default='Sorry, the json dict is invalid'
+        self.default_value={}
 
         #self.set_default='NOT NULL'
     
@@ -86,7 +87,7 @@ class JsonValueField(PhangoField):
         
         except json.JSONDecodeError:
                 
-            final_value={}
+            final_value='{}'
             self.error=True
             self.txt_error=self.error_default