openbsc: Decrease the version number of MNCC to 2 again

Currently OpenBSC and LCR are not compatible with each other.
So far we have only included patches that add new defines and
do not change the wire format of messages. Just revert it so
we can have LCR talk to OpenBSC
diff --git a/recipes-osmocom/openbsc/openbsc_git.bb b/recipes-osmocom/openbsc/openbsc_git.bb
index 1bf7bb3..7d395ca 100644
--- a/recipes-osmocom/openbsc/openbsc_git.bb
+++ b/recipes-osmocom/openbsc/openbsc_git.bb
@@ -1,9 +1,10 @@
 require ${PN}.inc
 
 PV = "0.13.0+gitr${SRCPV}"
-PR = "${INC_PR}.3"
+PR = "${INC_PR}.4"
 
 SRCREV = "8a158bb1ea36d0f88da18d0f034884b30f09fda2"
-SRC_URI += "git://git.osmocom.org/openbsc.git;protocol=git"
+SRC_URI += "git://git.osmocom.org/openbsc.git;protocol=git \
+    file://revert-mncc-version.patch"
 
 S = "${WORKDIR}/git/openbsc"