src/main: do not reject local bundles that do not have a .raucb extension
src/main: do not reject local bundles that do not have a .raucb extension

This is the first step in removing a long-lasting limitation on how to
name bundle to handle with RAUC.

While we still strongly recommend to use .raucb as the extensions for
bundle files, it should not be a strict requirement preventing people
who want to obfuscate their update solution by using some kind of
generic or custom file name extensions for bundle files.

Signed-off-by: Enrico Joerns <a2e5f936c390f36494e46e71bcfbe365bb1e8c49@pengutronix.de>

rauc/rauc,jluebbe/rauc,jluebbe/rauc,rauc/rauc,ejoerns/rauc,ejoerns/rauc,ejoerns/rauc,rauc/rauc,jluebbe/rauc