Bump commons-configuration2 from 2.4 to 2.6

Bumps commons-configuration2 from 2.4 to 2.6.

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

airsonic-main/pom.xml

@@ -412,7 +412,7 @@
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-configuration2</artifactId>
-            <version>2.4</version>
+            <version>2.6</version>
             <exclusions>
                 <exclusion>
                     <groupId>commons-logging</groupId>