Use master branch for acm installation

master branch used for the ACM installation.

Issue-ID: NONRTRIC-910
Signed-off-by: aravind.est <aravindhan.a@est.tech>
Change-Id: Ieec68e5b59270067c4472f7011b96fb482fed462
diff --git a/scripts/install/install-acm.sh b/scripts/install/install-acm.sh
index 76362e0..d08b86f 100755
--- a/scripts/install/install-acm.sh
+++ b/scripts/install/install-acm.sh
@@ -29,7 +29,7 @@
 IP_ADDRESS=$(hostname -I | awk '{print $1}')
 echo "IP Address : $IP_ADDRESS"
 
-git clone -b london "https://gerrit.onap.org/r/policy/docker"
+git clone "https://gerrit.onap.org/r/policy/docker"
 
 CWD=$(pwd)
 export WORKSPACE="$CWD/docker"