Merge pull request #4832 from nextcloud/dependabot/gradle/kotlin_version-1.3.60

Bump kotlin_version from 1.3.50 to 1.3.60

build.gradle

@@ -7,7 +7,7 @@
 import com.github.spotbugs.SpotBugsTask
 
 buildscript {
-    ext.kotlin_version = '1.3.50'
+    ext.kotlin_version = '1.3.60'
     repositories {
         google()
         jcenter()