Fix bug that prevented throttle angle correction working correctly when

using different values in different.

The cause was the IMU init code which triggered calculation was never
called after switching profiles - it couldn't be called twice because it
also initialised the compass.

The solution was to decouple compass initialisation from IMU
initialisation and extract the code to recalculate throttle angle scale
to a new method.

src/main/main.c

@@ -159,7 +159,12 @@ void init(void)
     LED0_OFF;
     LED1_OFF;
 
-    imuInit(); // Mag is initialized inside imuInit
+    imuInit();
+#ifdef MAG
+    if (sensors(SENSOR_MAG))
+        compassInit();
+#endif
+
     mixerInit(masterConfig.mixerConfiguration, masterConfig.customMixer);
 
     timerInit();