Set the MIRROR_PARSE_ERROR_LEVEL to info severity

Currently if parsing a mirror url list this results in an error, but the
worst that can happen is that no mirrors are used.

In contrast the error gives the user the impression that something has
failed completely.

p2-maven-plugin/src/main/java/org/eclipse/tycho/p2maven/DefaultProvisioningAgent.java

@@ -21,6 +21,8 @@
 import org.codehaus.plexus.component.annotations.Requirement;
 import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
 import org.codehaus.plexus.logging.Logger;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.equinox.internal.p2.artifact.repository.MirrorSelector;
 import org.eclipse.equinox.p2.core.IProvisioningAgent;
 import org.eclipse.equinox.p2.core.spi.IAgentServiceFactory;
 import org.eclipse.sisu.equinox.EquinoxServiceFactory;
@@ -29,6 +31,10 @@
 @Component(role = IProvisioningAgent.class)
 public class DefaultProvisioningAgent implements IProvisioningAgent {
 
+	static {
+		MirrorSelector.MIRROR_PARSE_ERROR_LEVEL = IStatus.INFO;
+	}
+
 	@Requirement
 	private Logger log;