Use property for flatten plugin version.

Signed-off-by: Olga Maciaszek-Sharma <[email protected]>

Author: OlgaMaciaszek

pom.xml

@@ -573,7 +573,7 @@
 				<plugin>
 					<groupId>org.codehaus.mojo</groupId>
 					<artifactId>flatten-maven-plugin</artifactId>
-					<version>1.5.0</version>
+					<version>${flatten-maven-plugin.version}</version>
 				</plugin>
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>