packaging: opensuse 15 fix docker and build gnutls

Correct the dockerfile for opensuse 15 replacing
 zypper --non-interactive  --gpg-auto-import-key refresh
by
 zypper --non-interactive  --gpg-auto-import-keys refresh
keyS must be in plural, otherwise the command fails

Update the spec files for opensuse 15 leap by compiling GnuTLS
    make -j4 V=1 .ffmpeg .gnutls

because when using the distro's GnuTLS 3.6.7  connections fail with
[TLS] handshake failed: An error has been detected in the library and
cannot continue operations.

Change-Id: I40a726e429b9f68447199f336ebe4a68ddfccf30

docker/Dockerfile_opensuse-leap_15.1

@@ -2,7 +2,7 @@ FROM opensuse/leap
 RUN zypper --non-interactive install  dnf
 RUN dnf clean all
 RUN zypper --non-interactive lr
-RUN zypper --non-interactive  --gpg-auto-import-key refresh
+RUN zypper --non-interactive  --gpg-auto-import-keys refresh
 RUN zypper --non-interactive lr
 RUN zypper --non-interactive  install -y dnf-command\(builddep\) rpmdevtools
 

packaging/rules/opensuse-leap/jami-one-click.spec

@@ -80,7 +80,7 @@ cd %{_builddir}/ring-project/daemon/contrib/native && \
     make list && \
     make fetch && \
     make -j4 V=1 && \
-    make -j4 V=1 .ffmpeg
+    make -j4 V=1 .ffmpeg .gnutls
 
 cd %{_builddir}/ring-project/daemon && \
     ./autogen.sh && \

packaging/rules/opensuse-leap/jami.spec

@@ -95,7 +95,7 @@ cd %{_builddir}/ring-project/daemon/contrib/native && \
     make list && \
     make fetch && \
     make -j4 V=1 && \
-    make -j4 V=1 .ffmpeg
+    make -j4 V=1 .ffmpeg .gnutls
 
 cd %{_builddir}/ring-project/daemon && \
     ./autogen.sh && \