restore sntp_set_timezone_in_seconds()

fixes #6678

Author: d-a-v

cores/esp8266/coredecls.h

@@ -20,6 +20,7 @@ void esp_yield();
 void esp_schedule();
 void tune_timeshift64 (uint64_t now_us);
 void disable_extra4k_at_link_time (void) __attribute__((noinline));
+bool sntp_set_timezone_in_seconds(uint32_t timezone);
 
 uint32_t sqrt32 (uint32_t n);
 uint32_t crc32 (const void* data, size_t length, uint32_t crc = 0xffffffff);

cores/esp8266/sntp-lwip2.cpp

@@ -65,7 +65,7 @@ extern "C" {
 
 static const char stod14[] PROGMEM = "settimeofday() can't set time!\n";
 bool sntp_set_timezone(sint8 timezone);
-bool sntp_set_timezone_in_seconds(sint32 timezone)
+bool sntp_set_timezone_in_seconds(uint32_t timezone)
 {
     return sntp_set_timezone((sint8)(timezone/(60*60))); //TODO: move this to the same file as sntp_set_timezone() in lwip1.4, and implement correctly over there.	
 }

cores/esp8266/sntp-lwip2.h

@@ -1,10 +1,6 @@
 #ifndef __sntp_lwip2_h__
 #define __sntp_lwip2_h__
 
-extern "C" {
-
-bool sntp_set_timezone_in_seconds(sint32 timezone);
-
-}
+#include <coredecls.h>
 
 #endif

cores/esp8266/time.cpp

@@ -78,6 +78,15 @@ int clock_gettime(clockid_t unused, struct timespec *tp)
 #define sntp_real_timestamp sntp_get_current_timestamp()
 #endif
 
+#if LWIP_VERSION_MAJOR == 2
+// backport api
+bool sntp_set_timezone_in_seconds (uint32_t timezone_sec)
+{
+    configTime(timezone_sec, 0, sntp_getservername(0), sntp_getservername(1), sntp_getservername(2));
+    return true;
+}
+#endif
+
 time_t time(time_t * t)
 {
     if (t)