[Taranis] Shorter WDT timeout was causing reboots when connecting/disconnecting USB

src/targets/taranis/board_taranis.cpp

@@ -149,7 +149,7 @@ void watchdogInit()
   IWDG->KR = 0x5555 ;      // Unlock registers
   IWDG->PR = 3 ;            // Divide by 32 => 1kHz clock
   IWDG->KR = 0x5555 ;      // Unlock registers
-  IWDG->RLR = 500 ;      // 0.5 seconds nominal
+  IWDG->RLR = 1500 ;      // 1.5 seconds nominal
   IWDG->KR = 0xAAAA ;      // reload
   IWDG->KR = 0xCCCC ;      // start
 }