Use 2020-03 on site builder

Change-Id: I56ea2605568e17ac14b71661ab0d0db3751928b3
Signed-off-by: Dawid Pakuła <zulus@w3des.net>
diff --git a/build/site/pom.xml b/build/site/pom.xml
index 2074cc1..3ae54bd 100644
--- a/build/site/pom.xml
+++ b/build/site/pom.xml
@@ -13,7 +13,7 @@
 		<tycho-groupid>org.eclipse.tycho</tycho-groupid>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<dltk-repository-url>file://${basedir}/../../update.site/target/site/</dltk-repository-url>
-		<eclipse-repository-url>http://download.eclipse.org/releases/mars/</eclipse-repository-url>
+		<eclipse-repository-url>http://download.eclipse.org/releases/2020-03/</eclipse-repository-url>
 	</properties>
 
 	<repositories>