Fixed bumpversion bug with RC versions (celery#2034)

Bump version: 5.3.6 → 5.3.7 (celery#1985)

Bump version: 5.3.5 → 5.3.6

Bump version: 5.3.4 → 5.3.5

Bump version: 5.3.3 → 5.3.4

Bump version: 5.3.2 → 5.3.3

Bump version: 5.3.1 → 5.3.2

Bump version: 5.3.0 → 5.3.1

Bump version: 5.3.0rc2 → 5.3.0

Bump version: 5.3.0rc1 → 5.3.0rc2