Add org.eclipse.m2e.core.prefs in .gitignore

Change-Id: Ia83ad27887123d654160094a15456e6543263376
diff --git a/.gitignore b/.gitignore
index 5c55d5e..dbf682e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,7 @@
 /.classpath
 /.project
 /.settings/org.maven.ide.eclipse.prefs
+/.settings/org.eclipse.m2e.core.prefs
 /test_site
 /.idea
 /gerrit-parent.iml