Make SecureCredentialsProvider public for reuse

The logic of looking into the secure.config for Git
credentials is very useful and could be reused in other
plugins.

The new pull-replication plugin depends on replication
already for reusing part of the implementation. Having this
class accessible would allow reducing the copy&paste in the
new plugin.

Change-Id: Iac9d591a14f16676ccda7dbf534bb4c96e39c160
diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/SecureCredentialsProvider.java b/src/main/java/com/googlesource/gerrit/plugins/replication/SecureCredentialsProvider.java
index c4294a9..62b4036 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/SecureCredentialsProvider.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/SecureCredentialsProvider.java
@@ -20,7 +20,7 @@
 import org.eclipse.jgit.transport.URIish;
 
 /** Looks up a remote's password in secure.config. */
-class SecureCredentialsProvider extends CredentialsProvider {
+public class SecureCredentialsProvider extends CredentialsProvider {
   private final String cfgUser;
   private final String cfgPass;