deb: fix 'debug-package-should-be-priority-extra' warning
deb: fix 'debug-package-should-be-priority-extra' warning

This commit adds Priority field for libhinawa-dbg package, to fix
the warning. See:
Lintian Tag: debug-package-should-be-priority-extra:
https://lintian.debian.org/tags/debug-package-should-be-priority-extra.html

Signed-off-by: Takashi Sakamoto <d5ec7d0cd8074757a1f5eb708bc105c3065a65ea@sakamocchi.jp>

takaswie/libhinawa,takaswie/libhinawa