contrib/jenkins.sh: "maintainer-clean" after "publish"

Run "make maintainer-clean" after publishing manuals, not the other way
around. Otherwise jenkins.sh fails when running for the master branch,
because docs/manuals/Makefile gets deleted although it is still needed
to publish the manuals.

Related: OS#3047
Fixes: 471fd92170 ("contrib/jenkins.sh: run "make maintainer-clean"")
Change-Id: I8ba5369b0948b61c68f43d807312c52465119aa5

contrib/jenkins.sh

@@ -61,10 +61,10 @@ LD_LIBRARY_PATH="$inst/lib" \
   DISTCHECK_CONFIGURE_FLAGS="--enable-vty-tests --enable-external-tests --enable-werror $CONFIG" \
   $MAKE distcheck \
   || cat-testlogs.sh
-$MAKE maintainer-clean
 
 if [ "$WITH_MANUALS" = "1" ] && [ "$PUBLISH" = "1" ]; then
 	make -C "$base/doc/manuals" publish
 fi
 
+$MAKE maintainer-clean
 osmo-clean-workspace.sh