updating gradle wrapper (to version 3.4)

CHANGELOG.md

 Upcoming version:
 -----------------
+  - updating gradle wrapper (to version 3.4) (Nikolaus Krismer)
   - fixed some issues with postgresql logs when using NFS for synced folders (Nikolaus Krismer)
   - using owner/group name for postgresql logs (Nikolaus Krismer)
   - changed hostname retrieval function (Nikolaus Krismer)

gradle/wrapper/gradle-wrapper.properties

-#Wed Jan 04 19:57:10 CET 2017
+#Mon Feb 27 14:14:08 CET 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-3.4-bin.zip