Merge pull request #9142 from nextcloud/bumpMasterTo3.19

Bump master to 3.19 alpha

build.gradle

@@ -87,7 +87,7 @@ repositories {
 
 // semantic versioning for version code
 def versionMajor = 3
-def versionMinor = 18
+def versionMinor = 19
 def versionPatch = 0
 def versionBuild = 0 // 0-50=Alpha / 51-98=RC / 90-99=stable