use a lowercase S in the server- prefix

Signed-off-by: David Festal <dfestal@redhat.com>

plugins/plugin-docker/che-plugin-docker-machine/src/main/java/org/eclipse/che/plugin/docker/machine/CustomServerEvaluationStrategy.java

@@ -383,7 +383,7 @@ protected void initPortMapping() {
             // add to this map only port without a known ref name
             Map<String, String> portsToUnkownRefName =
                     exposedPorts.stream().filter((port) -> !portsToKnownRefName.containsKey(port))
-                                .collect(Collectors.toMap(p -> p, p -> "Server-" + p.replace('/', '-')));
+                                .collect(Collectors.toMap(p -> p, p -> "server-" + p.replace('/', '-')));
 
             // list of all ports with refName (known/unknown)
             this.portsToRefName = new HashMap(portsToKnownRefName);