Fix *.sh build scripts

debian/build-vitastor-bullseye.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-sed 's/$REL/bullseye/' < vitastor.Dockerfile > ../Dockerfile
+sed 's/$REL/bullseye/g' < vitastor.Dockerfile > ../Dockerfile
 cd ..
 mkdir -p packages
 sudo podman build -v `pwd`/packages:/root/packages -f Dockerfile .

debian/build-vitastor-buster.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-sed 's/$REL/buster/' < vitastor.Dockerfile > ../Dockerfile
+sed 's/$REL/buster/g' < vitastor.Dockerfile > ../Dockerfile
 cd ..
 mkdir -p packages
 sudo podman build -v `pwd`/packages:/root/packages -f Dockerfile .