Fix accidental revert of .gnulib update

Change f88af9dc16cf891f88bb925885bdf5e328cf44df accidentally
reverted the .gnulib update from f3cfc99e794bd77479878fc224c6581b61d57dbd

* .gnulib: Update to 2c25c9ebe8db1415bfde25f0a451767332c8cf59

diff --git a/.gnulib b/.gnulib
index 64a5e38bced6c8f5117efbed95cdfd8ca133ed54..2c25c9ebe8db1415bfde25f0a451767332c8cf59 160000 (submodule)
--- a/.gnulib
+++ b/.gnulib
@@ -1 +1 @@
-Subproject commit 64a5e38bced6c8f5117efbed95cdfd8ca133ed54
+Subproject commit 2c25c9ebe8db1415bfde25f0a451767332c8cf59