[network-manager-openvpn] Use Unicode quotation marks in a new translatable string

[Piotr Drąg <piotrdrag src gnome org>]

commit 9e715208ef9c4df7d3152842a37dbb339fdf99ac
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Mon Aug 28 17:50:36 2017 +0200

    Use Unicode quotation marks in a new translatable string
    
    See https://developer.gnome.org/hig/stable/typography.html

 properties/import-export.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/properties/import-export.c b/properties/import-export.c
index 5d46b50..8bce07c 100644
--- a/properties/import-export.c
+++ b/properties/import-export.c
@@ -1095,7 +1095,7 @@ do_import (const char *path, const char *contents, gsize contents_len, GError **
 
                                if (params[3]) {
                                        if (!NM_IN_STRSET (params[3], NMOVPN_PROTCOL_TYPES)) {
-                                               line_error = g_strdup_printf (_("remote expects protocol type 
like 'udp' or 'tcp'"));
+                                               line_error = g_strdup_printf (_("remote expects protocol type 
like “udp” or “tcp”"));
                                                goto handle_line_error;
                                        }
                                }