`rdopkg.utils.specfile` already contains `get_magic_comment` function to read # magic_comment=value from .spec file. Add generic `set_magic_comment` function as well to modify magic comments and refactor `set_patches_base` to use it.
rdopkg.utils.specfilealready containsget_magic_commentfunction to readfrom .spec file.
Add generic
set_magic_commentfunction as well to modify magic comments and refactorset_patches_baseto use it.