pyngrok version needs update

[ryuliantoro]

When getting (bench get-app) this app from git, I got error:

frappe 13.19.0 requires pyngrok~=5.0.5, but you have pyngrok 5.1.0 which is incompatible.

Then tried to uninstall pyngrok 5.1.0 and install 5.0.6 it can be cloned and installed.

Frappe 13.19.0
No ERPNext
Ubuntu 20.04.3 LTS (Focal Fossa)

[jango-blockchained]

#38 , i've made a pull request.

The pyngrok vewrsion of this repo should be in sync with frappe, because it doesn't need other features.
Can be changed manuelly.