Remove the "Recent message" section from the bug reports

* lisp/mail/emacsbug.el (report-emacs-bug): Don't include "Recent
messages" since it has privacy implications.  Problem reported by
Lars Ingebrigtsen in:
https://lists.gnu.org/archive/html/emacs-devel/2019-11/msg01099.html
(bug#39185).

etc/NEWS

@@ -815,6 +815,11 @@ window after starting).  This variable defaults to nil.
 
 ** Miscellaneous
 
+---
+*** 'M-x report-emacs-bug' will no longer include "Recent messages" section.
+These were taken from the "*Messages*" buffer, and may inadvertently
+leak information from the reporting user.
+
 ---
 *** 'count-windows' now takes an optional parameter ALL-FRAMES.
 The semantics are as with 'walk-windows'.

lisp/mail/emacsbug.el

@@ -324,18 +324,6 @@ usually do not have translators for other languages.\n\n")))
     (let ((os (ignore-errors (report-emacs-bug--os-description))))
       (if (stringp os)
           (insert "System Description: " os "\n\n")))
-    (let ((message-buf (get-buffer "*Messages*")))
-      (if message-buf
-	  (let (beg-pos
-		(end-pos message-end-point))
-	    (with-current-buffer message-buf
-	      (goto-char end-pos)
-	      (forward-line -10)
-	      (setq beg-pos (point)))
-            (terpri (current-buffer) t)
-	    (insert "Recent messages:\n")
-	    (insert-buffer-substring message-buf beg-pos end-pos))))
-    (insert "\n")
     (when (and system-configuration-options
 	       (not (equal system-configuration-options "")))
       (insert "Configured using:\n 'configure "