bug: Modify proxy_rewrite plugin in dashboard,unable to save it

[chenyicai]

Issue description

When i modify proxy_rewrite plugin in dashboard, i can not save it
Fill in the configuration, click the confirm button, there is no response

Environment

• apisix version (cmd: apisix version): 2.0
• OS: centos 7

[juzhiyuan]

Will be resolved in 2.2 in 8 days.

[membphis]

you can make a try with 2.1.1 branch

[juzhiyuan]

you can make a try with 2.1.1 branch

🤔 this is a bug from plugin form, will be resolved by using code mirror.

[chenyicai]

When I upgraded to version 2.1.1, my problem was solved，thank you very much!