Use the main WorldEdit version for Sponge

worldedit-sponge/build.gradle

@@ -39,9 +39,6 @@ repositories {
 sourceCompatibility = 1.8
 targetCompatibility = 1.8
 
-version = "6.1.1"
-ext.internalVersion = version + ";" + gitCommitHash
-
 minecraft {
     version = "1.8.9"
     mappings = "stable_22"