release: add security/symbol checks to gitian

contrib/gitian-descriptors/gitian-linux.yml

@@ -97,6 +97,7 @@ script: |
     ./configure --prefix=${BASEPREFIX}/${i} --bindir=${INSTALLPATH}/bin --includedir=${INSTALLPATH}/include --libdir=${INSTALLPATH}/lib --disable-ccache --disable-maintainer-mode --disable-dependency-tracking ${CONFIGFLAGS}
     make ${MAKEOPTS}
     make ${MAKEOPTS} -C src check-security
+    make ${MAKEOPTS} -C src check-symbols
     make install-strip
     cd installed
     find . -name "lib*.la" -delete