tests: fix caching issue in test_ip_restriction_git

Following test failure is observed in
TestVCSOperations.test_ip_restriction_git:

―――――――――――――― TestVCSOperations.test_ip_restriction_git ――――――――――――――――――
kallithea/tests/other/test_vcs_operations.py:584: in test_ip_restriction_git
assert re.search(r'\b403\b', stderr)
E assert None
E + where None = <function search at 0x7fb9772da578>('\\b403\\b', "Cloning into '/tmp/kallithea-test-SZhXDz/vcs_operations-krPNvZ'...\n")
E + where <function search at 0x7fb9772da578> = re.search
------------------------- Captured stdout call ----------------------------
*** CMD git clone http://test_admin:test12@127.0.0.1:45291/vcs_test_git /tmp/kallithea-test-SZhXDz/vcs_operations-krPNvZ ***
stderr: "Cloning into '/tmp/kallithea-test-SZhXDz/vcs_operations-krPNvZ'...\n"



The test is setting up IP restrictions, verifying that access is no longer
possible, then clears the restriction. There already were sleeps after
clearing the restrictions, in order for the cache to expire and have the
setting take effect.
But there was no sleep on the enabling of the IP restriction, allowing
situations where the code would still run without restriction, and thus
allow the access, failing the test.

The failure has only been observed on test_ip_restriction_git, but the
change is also made for test_ip_restriction_hg.

The existing sleeps after restriction clearing are moved up to the 'finally'
clause to make it clear to which code they belong.