patch 8.2.3967: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more errors to errors.h.
diff --git a/src/spell.c b/src/spell.c
index 17b3ff8..21ffc3d 100644
--- a/src/spell.c
+++ b/src/spell.c
@@ -1246,7 +1246,7 @@
     if (!wp->w_p_spell || *wp->w_s->b_p_spl == NUL
 					 || wp->w_s->b_langp.ga_len == 0)
     {
-	emsg(_(e_no_spell));
+	emsg(_(e_spell_checking_is_not_possible));
 	return TRUE;
     }
     return FALSE;