use https.protocol for 1.7 build

Signed-off-by: olivier lamy <olamy@apache.org>
diff --git a/pom.xml b/pom.xml
index efb0b56..a3f4397 100644
--- a/pom.xml
+++ b/pom.xml
@@ -389,6 +389,8 @@
               <properties>
                 <useJvmChmod>${useJvmChmod}</useJvmChmod>
                 <testVersion>${testVersion}</testVersion>
+                <!-- e.g. ensure that Java7 picks up TLSv1.2 when connecting with Central -->
+                <https.protocols>${https.protocols}</https.protocols>
               </properties>
               <showVersion>true</showVersion>
             </configuration>