fix excel-exporter pom relative path

Author: eng-dedalus

knowage-excel-export/pom.xml

@@ -5,6 +5,7 @@
         <groupId>it.eng.knowage</groupId>
         <artifactId>knowage-ce-parent</artifactId>
         <version>9.0.0-SNAPSHOT</version>
+        <relativePath>../knowage-ce-parent/pom.xml</relativePath>
     </parent>
     <artifactId>knowage-excel-export</artifactId>
     <packaging>jar</packaging>