Upgrade com.nimbusds:nimbus-jose-jwt to 7.6

Fixes gh-7135

[closes #7135]

gradle/dependency-management.gradle

@@ -54,7 +54,7 @@ dependencyManagement {
 		dependency 'com.google.guava:guava:20.0'
 		dependency 'com.google.inject:guice:3.0'
 		dependency 'com.nimbusds:lang-tag:1.4.3'
-		dependency 'com.nimbusds:nimbus-jose-jwt:7.3'
+		dependency 'com.nimbusds:nimbus-jose-jwt:7.6'
 		dependency 'com.nimbusds:oauth2-oidc-sdk:6.13'
 		dependency 'com.squareup.okhttp3:okhttp:3.14.1'
 		dependency 'com.squareup.okio:okio:1.13.0'