修复M500模拟器轨迹跑完，反向行驶，导致数组越界问题

lib/socket/service/ProtocolSimulaterService.py

@@ -168,9 +168,11 @@ class ProtocolSimulaterService():
                     gpsMsg = self.genGPSMsg(latitude, longitude)
                     if self.fixPosition == 0:                             #是否固定当前位置的判断
                         if self.travelDirection == 0:
-                            self.gpsLineIndex = self.gpsLineIndex + 1     #正向行驶
+                            if self.gpsLineIndex < len(self.gpsLine):
+                                self.gpsLineIndex = self.gpsLineIndex + 1     #正向行驶
                         else:
-                            self.gpsLineIndex = self.gpsLineIndex - 1     #反向行驶
+                            if self.gpsLineIndex > 0:
+                                self.gpsLineIndex = self.gpsLineIndex - 1     #反向行驶
                 elif self.gpsLineIndex == len(self.gpsLine) or self.gpsLineIndex == -1:               #如果反向行驶和反向行驶刚好跑完
                     if int(self.data["travelData"]["travelLoop"]) == 0:                               #没有设置循环行驶
                         if self.travelDirection == 0: