patch 8.0.1773: dialog messages are not translated

Problem:    Dialog messages are not translated.
Solution:   Add N_() and _() where needed. (Sergey Alyoshin)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 29270ad..66d2ad6 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -9619,7 +9619,8 @@
 
 		browseFile = do_browse(BROWSE_SAVE,
 			(char_u *)_("Save Redirection"),
-			fname, NULL, NULL, BROWSE_FILTER_ALL_FILES, curbuf);
+			fname, NULL, NULL,
+			(char_u *)_(BROWSE_FILTER_ALL_FILES), curbuf);
 		if (browseFile == NULL)
 		    return;		/* operation cancelled */
 		vim_free(fname);
@@ -9845,7 +9846,8 @@
 		eap->cmdidx == CMD_mksession ? (char_u *)_("Save Session") :
 # endif
 		(char_u *)_("Save Setup"),
-		fname, (char_u *)"vim", NULL, BROWSE_FILTER_MACROS, NULL);
+		fname, (char_u *)"vim", NULL,
+		(char_u *)_(BROWSE_FILTER_MACROS), NULL);
 	if (browseFile == NULL)
 	    goto theend;
 	fname = browseFile;