Allow library git provider to try initialisation periodically.

[ateska]

The initialisation should be retried on_tick() till ".IsReady" == False.
If ".IsReady" == True, then the "pull" should be applied.

asab/asab/library/providers/git.py

Line 101 in b2c3ef6

async def initialize_git_repository(self):

This means that the git provider will be "self-healing", resistant to a failed start.