(SHIFT) build: add ShiftOS build support

Change-Id: I0bc4c6e792c0742c4b9f22cb1a3ff10f3ee711f5
Signed-off-by: Alexander Martinz <amartinz@shiftphones.com>
diff --git a/envsetup.sh b/envsetup.sh
index 2883348..c8376ef 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -157,7 +157,7 @@
     if (echo -n $1 | grep -q -e "^lineage_") ; then
         LINEAGE_BUILD=$(echo -n $1 | sed -e 's/^lineage_//g')
     else
-        LINEAGE_BUILD=
+        LINEAGE_BUILD=$1
     fi
     export LINEAGE_BUILD