fix: pom.xml to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-ORGBOUNCYCASTLE-1296075
- https://snyk.io/vuln/SNYK-JAVA-ORGBOUNCYCASTLE-2841508

pom.xml

@@ -143,7 +143,7 @@
 
         <!-- Others -->
         <commons-lang.version>2.6</commons-lang.version>
-        <apacheds.version>2.0.0.AM26</apacheds.version>
+        <apacheds.version>2.0.0.AM27</apacheds.version>
         <apacheds.codec.version>2.0.0</apacheds.codec.version>
         <google.zxing.version>3.4.0</google.zxing.version>
         <freemarker.version>2.3.32</freemarker.version>
@@ -281,7 +281,7 @@
         </developer>
     </developers>
 
-    <contributors></contributors>
+    <contributors/>
 
     <modules>
         <module>boms</module>