fix: false error message on cli plug with flags

(cherry picked from commit 14b98e3)

devtools/cli/src/main/java/io/quarkus/cli/QuarkusCli.java

@@ -12,6 +12,7 @@
 import java.util.Optional;
 import java.util.concurrent.Callable;
 import java.util.function.Supplier;
+import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
 import jakarta.inject.Inject;
@@ -176,7 +177,8 @@ public Optional<String> checkMissingCommand(CommandLine root, String[] args) {
                         .collect(Collectors.toList());
                 if (!unmatchedSubcommands.isEmpty()) {
                     missingCommand.append("-").append(unmatchedSubcommands.get(0));
-                    return Optional.of(missingCommand.toString());
+                    // We don't want the root itself to be added to the result
+                    return Optional.of(missingCommand.toString().replaceFirst(Pattern.quote(root.getCommandName() + "-"), ""));
                 }
 
                 currentParseResult = currentParseResult.subcommand();