Trim container-image configuration values

Fixes: quarkusio#19956
(cherry picked from commit ab8fa5e)

extensions/container-image/deployment/src/main/java/io/quarkus/container/image/deployment/ContainerImageConfig.java

@@ -5,6 +5,8 @@
 
 import io.quarkus.runtime.annotations.ConfigItem;
 import io.quarkus.runtime.annotations.ConfigRoot;
+import io.quarkus.runtime.annotations.ConvertWith;
+import io.quarkus.runtime.configuration.TrimmedStringConverter;
 
 @ConfigRoot
 public class ContainerImageConfig {
@@ -13,12 +15,14 @@ public class ContainerImageConfig {
      * The group the container image will be part of
      */
     @ConfigItem(defaultValue = "${user.name}")
+    @ConvertWith(TrimmedStringConverter.class)
     public Optional<String> group;
 
     /**
      * The name of the container image. If not set defaults to the application name
      */
     @ConfigItem(defaultValue = "${quarkus.application.name:unset}")
+    @ConvertWith(TrimmedStringConverter.class)
     public Optional<String> name;
 
     /**
@@ -95,6 +99,9 @@ public Optional<String> getEffectiveGroup() {
         if (group.isPresent()) {
             String originalGroup = group.get();
             if (originalGroup.equals(System.getProperty("user.name"))) {
+                if (originalGroup.isEmpty()) {
+                    return Optional.empty();
+                }
                 return Optional.of(originalGroup.toLowerCase().replace(' ', '-'));
             }
         }