disable TLS v1.3 protocol

We use Gradle coverall plugin to send the data generated by coverage
plugin to coverall.io, so our user can view the coverage report online.

However, the TLSv1.3 protocol used by JDK 11 is not supported by the
coverall.io, actually it gives the error bellow:

javax.net.ssl.SSLProtocolException: Connection reset by peer (Write failed)

Let’s disable TLSv1.3 protocol by restricting the scope of protocols in
gradle.properties.[1]

[1]kt3k/coveralls-gradle-plugin#85

gradle.properties

@@ -1,2 +1,3 @@
 org.gradle.parallel=false
 org.gradle.jvmargs=-XX:MaxMetaspaceSize=512m -XX:+HeapDumpOnOutOfMemoryError -Xmx1024m -Dfile.encoding=utf-8
+systemProp.jdk.tls.client.protocols="TLSv1,TLSv1.1,TLSv1.2"