install-deps.sh: install libtool-ltdl-devel for building python-saml

python-saml depends on dm.xmlsec.binding. which links against ltdl. so
without libtool-ltdl-devel, we will have

/opt/rh/devtoolset-7/root/usr/libexec/gcc/aarch64-redhat-linux/7/ld:
cannot find -lltdl

Signed-off-by: Kefu Chai <kchai@redhat.com>

install-deps.sh

@@ -270,7 +270,7 @@ else
 	$SUDO env DEBIAN_FRONTEND=noninteractive apt-get -y remove ceph-build-deps
 	install_seastar_deps
 	if [ -n "$backports" ] ; then rm $control; fi
-	    $SUDO apt-get install -y libxmlsec1 libxmlsec1-nss libxmlsec1-openssl libxmlsec1-dev
+	$SUDO apt-get install -y libxmlsec1 libxmlsec1-nss libxmlsec1-openssl libxmlsec1-dev
         ;;
     centos|fedora|rhel|ol|virtuozzo)
         yumdnf="yum"
@@ -330,7 +330,8 @@ else
             ensure_decent_gcc_on_rh $dts_ver
 	fi
         ! grep -q -i error: $DIR/yum-builddep.out || exit 1
-        $SUDO $yumdnf install -y xmlsec1 xmlsec1-nss xmlsec1-openssl xmlsec1-devel xmlsec1-openssl-devel
+        # for building python-saml and its dependencies
+        $SUDO $yumdnf install -y xmlsec1 xmlsec1-nss xmlsec1-openssl xmlsec1-devel xmlsec1-openssl-devel libtool-ltdl-devel
         ;;
     opensuse*|suse|sles)
         echo "Using zypper to install dependencies"