Add bash completion for docker build --network

Signed-off-by: Harald Albers <github@albersweb.de>

contrib/completion/bash/docker

@@ -1912,6 +1912,7 @@ _docker_image_build() {
 		--label
 		--memory -m
 		--memory-swap
+		--network
 		--shm-size
 		--tag -t
 		--ulimit
@@ -1944,6 +1945,20 @@ _docker_image_build() {
 			__docker_complete_isolation
 			return
 			;;
+		--network)
+			case "$cur" in
+				container:*)
+					__docker_complete_containers_all --cur "${cur#*:}"
+					;;
+				*)
+					COMPREPLY=( $( compgen -W "$(__docker_plugins --type Network) $(__docker_networks) container:" -- "$cur") )
+					if [ "${COMPREPLY[*]}" = "container:" ] ; then
+						__docker_nospace
+					fi
+					;;
+			esac
+			return
+			;;
 		--tag|-t)
 			__docker_complete_image_repos_and_tags
 			return