Get rid of Eclipse maven proxy

Should reduce many logs like:
```
[INFO] Artifact org.osgi:org.osgi.service.prefs:jar:1.1.2 is present in
the local repository, but cached from a remote repository ID that is
unavailable in current build context, verifying that is downloadable
from [central (https://repo.maven.apache.org/maven2, default, releases)]
```
from the build logs

Author: akurtakov

pom.xml

@@ -56,10 +56,6 @@
       <id>repo.eclipse.org</id>
       <url>https://repo.eclipse.org/content/groups/releases/</url>
     </pluginRepository>
-    <pluginRepository>
-      <id>Maven Central Proxy</id>
-      <url>https://repo.eclipse.org/content/repositories/maven_central/</url>
-    </pluginRepository>
     <pluginRepository>
       <id>tycho-snapshots</id>
       <url>https://repo.eclipse.org/content/repositories/tycho-snapshots/</url>