Fix app password visibility issues

accounts/tables.py

@@ -17,9 +17,9 @@ class AppPasswordTable(tables.Table):
 
     def value_key(self, value):
         out_val = "****"
-        if len(value) < 2:
+        if len(value) < 4:
             return out_val
-        return out_val + value[2:]
+        return out_val + value[-4:]
 
     def render_key(self, value):
         return self.value_key(value)