Fix gcode_T

Marlin/Marlin_main.cpp

@@ -6624,6 +6624,8 @@ inline void gcode_T(uint8_t tmp_extruder) {
     return;
   }
 
+  #if HOTENDS > 1
+
     float stored_feedrate = feedrate;
 
     if (code_seen('F')) {
@@ -6638,7 +6640,6 @@ inline void gcode_T(uint8_t tmp_extruder) {
       #endif
     }
 
-  #if HOTENDS > 1
     if (tmp_extruder != active_extruder) {
       bool no_move = code_seen('S') && code_value_bool();
       // Save current position to return to after applying extruder offset
@@ -6794,10 +6795,15 @@ inline void gcode_T(uint8_t tmp_extruder) {
       enable_solenoid_on_active_extruder();
     #endif // EXT_SOLENOID
 
-  #endif // HOTENDS > 1
-
     feedrate = stored_feedrate;
 
+  #else // !HOTENDS > 1
+
+    // Set the new active extruder
+    active_extruder = tmp_extruder;
+
+  #endif
+
   SERIAL_ECHO_START;
   SERIAL_ECHO(MSG_ACTIVE_EXTRUDER);
   SERIAL_PROTOCOLLN((int)active_extruder);