added itemis nexus repository for signing

releng/org.yakindu.sct.releng/pom.xml

@@ -291,6 +291,18 @@
 			<activation>
 				<activeByDefault>false</activeByDefault>
 			</activation>
+			<pluginRepositories>
+				<pluginRepository>
+					<id>nexus-projects.itemis.de</id>
+					<url>https://projects.itemis.de/nexus/content/groups/maven-plugins/</url>
+					<releases>
+						<enabled>true</enabled>
+					</releases>
+					<snapshots>
+						<enabled>true</enabled>
+					</snapshots>
+				</pluginRepository>
+			</pluginRepositories>
 			<build>
 				<plugins>
 					<plugin>