spdxdebian: patch command fails with Debian Format 1.0 non-native

In order to fetch debian/control and debian/copyright files, in debian 1.0 non-native format packages we need to apply the debian patch to the original sources. The command is failing for some packages, eg.

21-10-28 16:35:00 DEBUG    aliens4friends.commands.spdxdebian  | [dhcp-4.4.2-r0] Files determined through userland/dhcp/4.4.2-r0/dhcp-4.4.2-r0.snapmatch.json
21-10-28 16:35:00 DEBUG    aliens4friends.commands.spdxdebian  | [dhcp-4.4.2-r0] Debian source format 1.0 (non-native) processing patch
21-10-28 16:35:00 ERROR    aliens4friends.commands.command     | Exception: Command 'patch -p1 < /tmp/tmpf3ks5ewx/dhcp_2.0pl5dfsg1-20.2.diff' failed. Output is:
can't find file to patch at input line 3
Perhaps you used the wrong -p or --strip option?