Trim trailing slash from REPOSITORY_BASE before add-apt-repository

Change-Id: Ic052f6d41d3d46c99ffcdc399febb875566b2672
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>

jenkins/common/install_common

@@ -45,4 +45,5 @@ key_location=$REPOSITORY_BASE/$RELEASE/$REPOSITORY_KEY
 
 curl $key_location | apt-key add -
 
+REPOSITORY_BASE=${REPOSITORY_BASE%/}
 apt-get update && add-apt-repository -y "deb $REPOSITORY_BASE/$RELEASE $REPOSITORY SO UI RO IM osmclient openvim"