Revert "po: Remove translated expanded-acronym"

This change is not needed after the real fix:
"its: Fix translation matching rules"

So revert it to avoid having conflicting versions of the same
translation in Transifex and checked out.

This reverts commit a4aaf578.
1 job for wip/hadess/no-acronym-translation in 2 minutes and 55 seconds (queued for 57 seconds)
Status Job ID Name Coverage
  Test
failed #592612
build

00:02:55

 
Name Stage Failure
failed
build Test
fi
./freedesktop.org.xml:25081: element expanded-acronym: validity error : No declaration for attribute lang of element expanded-acronym
<expanded-acronym xml:lang="be-Latn">Metafajł Computer Graphics</expanded-a
^
./freedesktop.org.xml:25083: element mime-type: validity error : Element mime-type content does not follow the DTD, expecting (comment+ , (acronym , expanded-acronym)? , (icon | generic-icon | glob | magic | treemagic | root-XML | alias | sub-class-of)*), got (comment comment comment comment comment comment acronym expanded-acronym expanded-acronym glob )
</mime-type>
^
make: *** [Makefile:1224: check] Error 1
ERROR: Job failed: exit code 1