package/libgpg-error: Fix typo

package/libgpg-error: Fix typo

Fix autobuilders failures:
http://autobuild.buildroot.net/results/a45/a45d4310e9313d7e12a584e373c54916b5502d32/
http://autobuild.buildroot.net/results/3e0/3e09ed66bc9705ce6e02560f792f1872e2ff438a/
http://autobuild.buildroot.net/results/3f5/3f588651bd8565962274d6f7930c7c7031ca26af/
http://autobuild.buildroot.net/results/779/77955a015d6027544b4ba2cb5098cc83fc7bcfce/
http://autobuild.buildroot.net/results/215/215c4a5512b9b7bd9c302e46618fa7319c6dc293/

Signed-off-by: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>