[PATCH 7/9] wispr: Change online check urls to const char*

The struct connman_wispr_portal_context already has these as const, and
the changed connman_setting_get_string() returns a const char*, so
change these as well.
---
 src/wispr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/wispr.c b/src/wispr.c
index a40cf353..77d1e11f 100644
--- a/src/wispr.c
+++ b/src/wispr.c
@@ -142,8 +142,8 @@ static bool wispr_portal_web_result(const GError *error, GWebResult *result, gpo
  */
 static GHashTable *wispr_portal_hash = NULL;
 
-static char *online_check_ipv4_url = NULL;
-static char *online_check_ipv6_url = NULL;
+static const char *online_check_ipv4_url = NULL;
+static const char *online_check_ipv6_url = NULL;
 
 static const struct wispr_portal_context_route_ops
 	ipv4_wispr_portal_context_route_ops = {
-- 
2.47.3