Update to Gradle 4.0

• Remove the misc/compat9x dependency since the bundled native-platform no longer depends on libstdc++.so.6
• Fix MASTER_SITES: Both {https,http}://services.gradle.org redirect to https://downloads.gradle.org
• Set EXTRACT_SUFX instead of setting WRKSRC + DISTNAME

PR: 220322
Submitted by: timp87@gmail.com
Approved by: mat (mentor), gasol.wu@gmail.com (maintainer timeout, 2 weeks)
Differential Revision: https://reviews.freebsd.org/D11565