`appdir-lint.sh` need to detect `*.metainfo.xml` if `*appdata.xml` not availiable

[shenlebantongying]

pkg2appimage/appdir-lint.sh

Lines 124 to 129 in c302f81

	# Find the relevant appdata.xml file;
	# according to ximion, usr/share/appdata is a legacy path replaced by usr/share/metainfo
	APPDATA=$(ls "${APPDIR}"/usr/share/metainfo/*appdata.xml 2>/dev/null | head -n 1) # TODO: Handle more than one better
	if [ -z "$APPDATA" ] ; then
	APPDATA=$(ls "${APPDIR}"/usr/share/appdata/*appdata.xml 2>/dev/null | head -n 1) # TODO: Handle more than one better
	fi

[shenlebantongying]

Appstream's fault.

[Korne127]

What do you mean with Appstream's fault / why did you close this?

[shenlebantongying]

What do you mean with Appstream's fault

Changing the widely used name/path and requiring the entire ecosystem to change is generally a insane and horrific thing to do.

why did you close this?

I forget why, maybe misclick.

[Korne127]

Yeah, I agree :/

[probonopd]

These files are entirely optional as per the AppImageSpec, aren't they?