CurrentSchemaVersion: Allow to use it in plugins

To implement dedicated databases in plugin based on GWTORM, current
version plays important role in upgrading schema version. Change
the modifiers for the attributes and the constructor to allow this.

Gerrit CI plugin needs this to support schema upgrade in init plugin
step.

Change-Id: I372be503cff79a48d1320244e625bc7c5635eca5
diff --git a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/CurrentSchemaVersion.java b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/CurrentSchemaVersion.java
index 183bb1e..cba5d41 100644
--- a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/CurrentSchemaVersion.java
+++ b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/CurrentSchemaVersion.java
@@ -26,7 +26,7 @@
     private static final String VALUE = "X";
 
     @Column(id = 1, length = 1)
-    protected String one = VALUE;
+    public String one = VALUE;
 
     public Key() {
     }
@@ -50,12 +50,12 @@
   }
 
   @Column(id = 1)
-  protected Key singleton;
+  public Key singleton;
 
   /** Current version number of the schema. */
   @Column(id = 2)
   public transient int versionNbr;
 
-  protected CurrentSchemaVersion() {
+  public CurrentSchemaVersion() {
   }
 }