MINOR: converters: give the session pointer as converter argument

Some usages of the converters need to know the attached session. The Lua
needs the session for retrieving his running context. This patch adds
the "session" as an argument of the converters prototype.
diff --git a/src/proto_http.c b/src/proto_http.c
index 3738aa4..f3444e9 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -11377,7 +11377,8 @@
  * adds an optional offset found in args[0] and emits a string representing
  * the date in RFC-1123/5322 format.
  */
-static int sample_conv_http_date(const struct arg *args, struct sample *smp, void *private)
+static int sample_conv_http_date(struct session *session, const struct arg *args,
+                                 struct sample *smp, void *private)
 {
 	const char day[7][4] = { "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" };
 	const char mon[12][4] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
@@ -11428,7 +11429,8 @@
 }
 
 /* Arguments: The list of expected value, the number of parts returned and the separator */
-static int sample_conv_q_prefered(const struct arg *args, struct sample *smp, void *private)
+static int sample_conv_q_prefered(struct session *session, const struct arg *args,
+                                  struct sample *smp, void *private)
 {
 	const char *al = smp->data.str.str;
 	const char *end = al + smp->data.str.len;