fix: pom.xml to reduce vulnerabilities (#1024)

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-COMFASTERXMLJACKSONCORE-455617

Author: snyk-bot

pom.xml

@@ -72,7 +72,7 @@
     <bouncy.version>1.60</bouncy.version>
 
     <junit.version>4.12</junit.version>
-    <jackson.version>2.9.9</jackson.version>
+    <jackson.version>2.10.0.pr1</jackson.version>
     <jackson.databind.version>2.9.9.2</jackson.databind.version>
     <assertj.version>3.10.0</assertj.version>