vim-patch:8.0.0547: extra line break in verbosefile

Problem:    Extra line break in verbosefile when using ":echomsg". (Ingo
            Karkat)
Solution:   Don't call msg_start(). (closes vim/vim#1618)
52604f2454

src/nvim/eval.c

@@ -19533,7 +19533,6 @@ void ex_execute(exarg_T *eap)
       // follows is displayed on a new line when scrolling back at the
       // more prompt.
       msg_sb_eol();
-      msg_start();
     }
 
     if (eap->cmdidx == CMD_echomsg) {