POM: fix forum.image.sc tag link

The Discourse software updated the tags path from /tags/ to /tag/.

Author: StephanPreibisch

pom.xml

@@ -103,7 +103,7 @@
 	<mailingLists>
 		<mailingList>
 			<name>Image.sc Forum</name>
-			<archive>https://forum.image.sc/tags/multiview-reconstruction</archive>
+			<archive>https://forum.image.sc/tag/multiview-reconstruction</archive>
 		</mailingList>
 	</mailingLists>