[3.9.x][MNG-8109] Resolver 1.9.20 (#1490)

Update resolver to 1.9.20.

---

https://issues.apache.org/jira/browse/MNG-8109

Author: cstamas

pom.xml

@@ -147,7 +147,7 @@ under the License.
     <securityDispatcherVersion>2.0</securityDispatcherVersion>
     <cipherVersion>2.0</cipherVersion>
     <jxpathVersion>1.3</jxpathVersion>
-    <resolverVersion>1.9.19</resolverVersion>
+    <resolverVersion>1.9.20</resolverVersion>
     <slf4jVersion>1.7.36</slf4jVersion>
     <xmlunitVersion>2.9.1</xmlunitVersion>
     <powermockVersion>2.0.9</powermockVersion>