Use SPDX 3.0 license identifier

SPDX released version 3 of their license list (<https://spdx.org/licenses/>),
which changed the FSF licenses to explicitly end in -only or -or-later
instead of relying on an easy to miss + symbol.

Bug: T183858
Change-Id: Id75a37eab27282ca7797fa3e6ceb92750c59477f

data/fontrepo/fonts/Nazli/font.ini

@@ -1,7 +1,7 @@
 [Nazli]
 languages=fa
 version=0.4
-license=GPL-2.0
+license=GPL-2.0-only
 licensefile=gpl-2.0.txt
 request-url=https://gerrit.wikimedia.org/r/#/c/76349/
 url=http://persian-computing.org/