Bump postgresql from 42.2.19 to 42.2.20

Bumps [postgresql](https://github.com/pgjdbc/pgjdbc) from 42.2.19 to 42.2.20.
- [Release notes](https://github.com/pgjdbc/pgjdbc/releases)
- [Changelog](https://github.com/pgjdbc/pgjdbc/blob/REL42.2.20/CHANGELOG.md)
- [Commits](pgjdbc/pgjdbc@REL42.2.19...REL42.2.20)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -307,7 +307,7 @@
     <dependency>
       <groupId>org.postgresql</groupId>
       <artifactId>postgresql</artifactId>
-      <version>42.2.19</version>
+      <version>42.2.20</version>
       <scope>test</scope>
     </dependency>
   </dependencies>