Fix JavaDoc warning

The {@link} tag cannot handle links to packages; remove it.

Change-Id: I25a38418b3adb5d29322e244b097dd8049b037e9
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/CommonConverters.java b/gerrit-server/src/main/java/com/google/gerrit/server/CommonConverters.java
index 09c2ea6..be07bde 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/CommonConverters.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/CommonConverters.java
@@ -21,7 +21,7 @@
 import java.sql.Timestamp;
 
 /**
- * Converters to classes in {@link com.google.gerrit.extensions.common}.
+ * Converters to classes in {@code com.google.gerrit.extensions.common}.
  * <p>
  * The server frequently needs to convert internal types to types exposed in the
  * extension API, but the converters themselves are not part of this API. This