Add option to edit mirror interval on repo push mirrors

[6543]

at the moment you have to recreate a push mirror if you want to change the interval :/

[CypherpunkSamurai]

Hello @6543,

I would like to contribute to this issue, I've worked on golang projects before, and would like to work on gitea. how can i get started? :)

[the-writer-dev]

@6543 Could you assign this to me?

[puni9869]

If we are still looking this issue to be fixed. I can take this forward. Please assign me.

[puni9869]

As per my understanding
we have mininum 10 minute default periodic sync time when we setting up any mirror and once we done setting as below

screen shot

We don't have option to edit the periodic time in existing setted up push mirror.

So in this ticket we want that small feature so that we don't have to recreate the mirror again and again.

@jolheiser