make OpenJPA version, used twice, a variable, instead of repeating it

fineract-provider/build.gradle

@@ -28,6 +28,9 @@ project.ext.jerseyVersion = '1.17'
 project.ext.springDataJpaVersion = '1.7.0.RELEASE' // also change spring-boot-gradle-plugin version below
 
 buildscript {
+  ext {
+    openJPAVersion = '2.4.1'
+  }
   repositories {
   	 jcenter()
   	 mavenCentral()
@@ -39,7 +42,7 @@ buildscript {
                'nl.javadude.gradle.plugins:license-gradle-plugin:0.11.0',
                'org.zeroturnaround:gradle-jrebel-plugin:1.1.2',
                'org.springframework.boot:spring-boot-gradle-plugin:1.1.6.RELEASE' // also change springDataJpaVersion above
-     classpath 'org.apache.openjpa:openjpa-all:2.4.1'
+     classpath "org.apache.openjpa:openjpa-all:$openJPAVersion"
      classpath 'at.schmutterer.oss.gradle:gradle-openjpa:0.2.0'
      classpath 'gradle.plugin.org.nosphere.apache:creadur-rat-gradle:0.2.2'
   }

fineract-provider/dependencies.gradle

@@ -42,8 +42,7 @@ dependencies {
 				
 	       		[group: 'org.springframework.security.oauth', name: 'spring-security-oauth2', version: springOauthVersion],
 
-                [group: 'org.apache.openjpa', name:'openjpa-all', version:'2.4.1'],
-                //[group: 'org.apache.openjpa', name:'openjpa-maven-plugin', version:'2.4.1'],
+                [group: 'org.apache.openjpa', name:'openjpa-all', version: openJPAVersion],
                 //[group: 'javax.ws.rs', name: 'jsr311-api', version: '1.1.1'],
                 [group: 'com.sun.jersey', name: 'jersey-core', version: jerseyVersion],
                 [group: 'com.sun.jersey', name: 'jersey-servlet', version: jerseyVersion],