LfsGson: Remove unnecessary @since tag

The tag is formed inconsistently to tags in the rest of the JGit code
base (i.e. "4.10.0" with a trailing ".0" where all the others don't).

However since this class is not in the public API, the @since tag is
not necessary and can just be removed.

Change-Id: Ifa3f543f819a39453fcf343278e522b5d7b003c3
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

org.eclipse.jgit.lfs.server/src/org/eclipse/jgit/lfs/server/internal/LfsGson.java

@@ -53,8 +53,6 @@ import com.google.gson.JsonSyntaxException;
 
 /**
  * Wrapper for {@link com.google.gson.Gson} used by LFS servlets.
- *
- * @since 4.10.0
  */
 public class LfsGson {
 	private static final Gson gson = new GsonBuilder()