libssh2.pc.in: fix the output of pkg-config --libs

... such that it does not include LDFLAGS used to build libssh2 itself.
There was a similar fix in the curl project long time ago:

https://github.com/bagder/curl/commit/curl-7_19_7-56-g4c8adc8

Bug: https://bugzilla.redhat.com/1279966
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
1 file changed