pom.xml: Bump nexus-staging-maven-plugin to 1.6.14

Fixes a crash when I did a dry run deploy locally

Author: robinjam

pom.xml

@@ -190,7 +190,7 @@
             <plugin>
                 <groupId>org.sonatype.plugins</groupId>
                 <artifactId>nexus-staging-maven-plugin</artifactId>
-                <version>1.6.7</version>
+                <version>1.6.14</version>
                 <extensions>true</extensions>
                 <configuration>
                     <serverId>ossrh-staging-api</serverId>