rebase: don't link with gentoo

the package doesn't exist there and finds a wrong one

rebase/PKGBUILD

@@ -7,6 +7,9 @@ pkgdesc="The Cygwin rebase distribution contains four utilities, rebase, rebasea
 arch=('i686' 'x86_64')
 license=('custom')
 url="https://www.cygwin.com/"
+msys2_references=(
+  'gentoo'
+)
 depends=('dash')
 makedepends=('coreutils' 'git' 'grep' 'gzip' 'sed' 'autotools' 'gcc')
 # options=('debug' '!strip')