Fix PR reference URL and body

Use the human-readable GitHub PR URL
when creating the Gerrit Change and keep the
original PR body formatting.

Change-Id: Ib9ec6255b6a3f20af1495a703441705b07bfb1ee
diff --git a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/git/PullRequestImportJob.java b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/git/PullRequestImportJob.java
index 646737e..601e438 100644
--- a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/git/PullRequestImportJob.java
+++ b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/git/PullRequestImportJob.java
@@ -234,11 +234,11 @@
 
   private String getChangeMessage(GHPullRequest pr) {
     return "GitHub Pull Request: "
-        + pr.getUrl()
+        + pr.getHtmlUrl()
         + "\n\n"
         + pr.getTitle()
         + "\n\n"
-        + pr.getBody().replaceAll("\n", "\n\n");
+        + pr.getBody();
   }
 
   private void exitWhenCancelled() throws JobCancelledException {