Remove +dfsg* from docker version (#2757)

On some Debian installations, the following command
    docker version --format '{{.Server.Version}}'
returns a version number with +dfsg... added, for example:
    20.10.5+dfsg1

After removing the dots, the comparison of DOCKER_VERSION with
MIN_DOCKER_VERSION throws
./buildContainerImage.sh: line 97: [: 20105+dfsg1: integer expression expected

This pull request also adds the substring +dfsg* from the
version number in order for the comparison to have numerical values
on both sides.

Author: ReneNyffenegger

OracleDatabase/SingleInstance/dockerfiles/buildContainerImage.sh

@@ -89,6 +89,10 @@ checkDockerVersion() {
   # Get Docker Server version
   echo "Checking Docker version."
   DOCKER_VERSION=$("${CONTAINER_RUNTIME}" version --format '{{.Server.Version }}'|| exit 0)
+  # Remove +dfsg* if present
+  DOCKER_VERSION=${DOCKER_VERSION%%+dfsg*}
+  # Remove dot in Docker version
+  DOCKER_VERSION=${DOCKER_VERSION//./}
 
   if [ "$(printf '%s\n' "$MIN_DOCKER_VERSION" "$DOCKER_VERSION" | sort -V | head -n1)" != "$MIN_DOCKER_VERSION" ]; then
     echo "Docker version is below the minimum required version ${MIN_DOCKER_VERSION}"