libstrophe: add a patch to fix static builds

libstrophe.a and libcrypto.a have symbols with equal names, so
executables can't be statically linked with libstrophe and openssl:

sha1dgst.c:(.text+0x1b4c): multiple definition of `SHA1_Update'
sha1dgst.c:(.text+0x1cc0): multiple definition of `SHA1_Final'
sha1dgst.c:(.text+0x1e78): multiple definition of `SHA1_Init

Renaming the internal SHA functions fixes the problem.

Issue reported upstream:

  https://github.com/strophe/libstrophe/issues/40

Fixes:

  http://autobuild.buildroot.net/results/047/047e319b9d7bf0cdaabc007326a6d67de2c1ee52/



Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>