[Java] Remove useless assigment of version/group in the ext block

Author: vyazelenko

build.gradle

@@ -40,8 +40,6 @@ def sbeGroup = 'uk.co.real-logic'
 def sbeVersion = file('version.txt').text.trim()
 
 ext {
- group = sbeGroup
- version = sbeVersion
  isReleaseVersion = !version.endsWith('-SNAPSHOT')
  releasesRepoUrl = 'https://oss.sonatype.org/service/local/staging/deploy/maven2/'
  snapshotsRepoUrl = 'https://oss.sonatype.org/content/repositories/snapshots/'