build,ci: apply fixes to make pomchecker happy

Author: poikilotherm

pom.xml

@@ -31,6 +31,7 @@
     <name>XOAI : OAI-PMH Java Toolkit</name>
     <!--<url>https://github.com/gdcc/xoai</url>-->
     <description>An OAI-PMH data and/or service provider implementation, integration ready for your service.</description>
+    <url>https://github.com/${project.github.org}/${project.github.repo}</url>
 
     <properties>
         <jdk.version>11</jdk.version>
@@ -57,10 +58,6 @@
         </license>
     </licenses>
 
-    <scm>
-        <tag>xoai-5.2.1</tag>
-    </scm>
-
     <build>
         <plugins>
             <!-- META -->