patch 8.2.3961: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more errors to errors.h.
diff --git a/src/clipboard.c b/src/clipboard.c
index 38596f5..09d05c9 100644
--- a/src/clipboard.c
+++ b/src/clipboard.c
@@ -1305,12 +1305,12 @@
 	    p += 8;
 	    new_exclude_prog = vim_regcomp(p, RE_MAGIC);
 	    if (new_exclude_prog == NULL)
-		errmsg = e_invarg;
+		errmsg = e_invalid_argument;
 	    break;
 	}
 	else
 	{
-	    errmsg = e_invarg;
+	    errmsg = e_invalid_argument;
 	    break;
 	}
 	if (*p == ',')