patch 9.0.1572: error messages are not translated

Problem:    Error messages are not translated.
Solution:   Add _().
diff --git a/src/main.c b/src/main.c
index 476d869..0e8e82c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3198,7 +3198,7 @@
 	{
 	    if (do_source((char_u *)VIM_DEFAULTS_FILE, FALSE, DOSO_NONE, NULL)
 									 != OK)
-		emsg(e_failed_to_source_defaults);
+		emsg(_(e_failed_to_source_defaults));
 	}
 	else if (STRCMP(parmp->use_vimrc, "NONE") == 0
 				     || STRCMP(parmp->use_vimrc, "NORC") == 0)
@@ -3273,7 +3273,7 @@
 		// When no .vimrc file was found: source defaults.vim.
 		if (do_source((char_u *)VIM_DEFAULTS_FILE, FALSE, DOSO_NONE,
 								 NULL) == FAIL)
-		    emsg(e_failed_to_source_defaults);
+		    emsg(_(e_failed_to_source_defaults));
 	    }
 	}