Use HTTPS for repo1.maven.org

Upstream no longer supports plain HTTP as of today [1].

[1] https://support.sonatype.com/hc/en-us/articles/360041287334
diff --git a/contrib/fb303/java/build.properties b/contrib/fb303/java/build.properties
index 8463668..845048c 100644
--- a/contrib/fb303/java/build.properties
+++ b/contrib/fb303/java/build.properties
@@ -1,5 +1,5 @@
 # Maven Ant tasks Jar details
 mvn.ant.task.version=2.1.3
-mvn.repo=http://repo1.maven.org/maven2
+mvn.repo=https://repo1.maven.org/maven2
 mvn.ant.task.url=${mvn.repo}/org/apache/maven/maven-ant-tasks/${mvn.ant.task.version}
 mvn.ant.task.jar=maven-ant-tasks-${mvn.ant.task.version}.jar