maemo/gtk+2.0-maemo: remove version from provides (!853)

With this patch and pmbootstrap!1851, finally resolve the long-standing
issue that gtk+2.0-maemo would get installed by pmbootstrap whenever
something depends on gtk+2.0. (Currently on x86_64 only, because maemo
is disabled for other arches, but still very annoying.)

I've verified that doing 'pmbootstrap install' with qemu-amd64 and
hildon as selected UI still results in gtk+2.0-maemo getting installed.

[ci:skip-build]: already built successfully in CI

maemo/gtk+2.0-maemo/APKBUILD

@@ -4,7 +4,7 @@
 pkgname=gtk+2.0-maemo
 pkgver=2.24.31
 _tag=2.24.25
-pkgrel=6
+pkgrel=7
 subpkg=gtk-update-icon-cache
 pkgdesc="The GTK+ Toolkit (v2)"
 url="http://www.gtk.org/"
@@ -17,7 +17,7 @@ subpackages="$pkgname-dev $subpkg:icon_cache"
 depends="shared-mime-info gtk-update-icon-cache"
 
 replaces="gtk+ gtk+-dev gtk+-doc"
-provides="gtk+2.0=$pkgver"
+provides="gtk+2.0"
 
 depends_dev="
 	atk-dev