Fix flatten plugin setup.

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

Author: OlgaMaciaszek

pom.xml

@@ -66,6 +66,7 @@
 		<xerces.version>2.12.2</xerces.version>
 		<jacoco-maven-plugin.version>0.8.8</jacoco-maven-plugin.version>
 		<exec-maven-plugin.version>1.6.0</exec-maven-plugin.version>
+		<flatten-maven-plugin.version>1.5.0</flatten-maven-plugin.version>
 
 		<contract.kotlin.version>1.8.22</contract.kotlin.version>
 		<commons-beanutils.version>1.9.4</commons-beanutils.version>
@@ -560,7 +561,7 @@
 				<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>
@@ -621,6 +622,10 @@
 					<skip>true</skip>
 				</configuration>
 			</plugin>
+			<plugin>
+				<groupId>org.codehaus.mojo</groupId>
+				<artifactId>flatten-maven-plugin</artifactId>
+			</plugin>
 		</plugins>
 	</build>