* mu4e-headers: use 'S' for editing the last query, to be consistent with mu4e-view

emacs/mu4e-headers.el

@@ -301,7 +301,7 @@ after the end of the search results."
     (let ((map (make-sparse-keymap)))
 
       (define-key map "s" 'mu4e-headers-search)
-      (define-key map "e" 'mu4e-headers-search-edit)
+      (define-key map "S" 'mu4e-headers-search-edit)
       (define-key map "/" 'mu4e-headers-search-narrow)
 
       (define-key map "j" 'mu4e~headers-jump-to-maildir)

emacs/mu4e.texi

@@ -534,7 +534,7 @@ n,p          go to next, previous message
 y            select the message view (if it's visible)
 
 s            search
-e            edit last query
+S            edit last query
 /            narrow the search
 b            search bookmark
 B            edit bookmark before search