Always rebuild the swing jar before shading it

Without forceCreation, maven-jar-plugin kept the previous shaded
ts3-client.jar when the module's classes were unchanged, and the shade then
used it as input: the stale ts3j classes inside it won over the freshly
installed ts3j, so ts3j fixes never reached the built client without a clean.

Also updates ts3j for the empty server-group parsing fix.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ts3-client/swing/pom.xml

@@ -50,6 +50,19 @@
     <build>
         <finalName>ts3-client</finalName>
         <plugins>
+            <!--
+                The shade plugin replaces ts3-client.jar with the shaded jar. Without
+                forceCreation, a build where this module's classes did not change keeps
+                that shaded jar as the input to the next shade, and the stale copies of
+                the dependencies inside it (ts3j in particular) win over the fresh ones.
+            -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <configuration>
+                    <forceCreation>true</forceCreation>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-shade-plugin</artifactId>