Correct error in build.sh

scripts/build.sh

@@ -121,7 +121,7 @@ for target in "${TARGETS[@]}" ; do
 	merge+=("$origdir/manifest.merge.json")
     [ "$beta" -a -f "$sourcedir/manifest.beta.merge.json" ] && \
 	merge+=("$sourcedir/manifest.beta.merge.json")
-    [ "$origdir" -a "$beta" -a -f "$sourcedir/manifest.beta.merge.json" ] && \
+    [ "$origdir" -a "$beta" -a -f "$origdir/manifest.beta.merge.json" ] && \
 	merge+=("$origdir/manifest.beta.merge.json")
 
     override=()