HUB75 bugfix - preserve chain length parameter

chain length was always replaced with "4"

wled00/bus_manager.h

@@ -64,7 +64,7 @@ struct BusConfig {
     if ((type >= TYPE_NET_DDP_RGB) && (type < (TYPE_NET_DDP_RGB + 16))) nPins = 4;     // virtual network bus. 4 "pins" store IP address
     else if ((type > 47) && (type < 63)) nPins = 2;                                    // (data + clock / SPI) busses - two pins
     else if (IS_PWM(type)) nPins = NUM_PWM_PINS(type);                                 // PWM needs 1..5 pins
-    else if (type >= TYPE_HUB75MATRIX && type <= (TYPE_HUB75MATRIX + 10)) nPins = 0;   // HUB75 does not use LED pins
+    else if (type >= TYPE_HUB75MATRIX && type <= (TYPE_HUB75MATRIX + 10)) nPins = 1;   // HUB75 does not use LED pins, but we need to preserve the "chain length" parameter
     for (uint8_t i = 0; i < min(unsigned(nPins), sizeof(pins)/sizeof(pins[0])); i++) pins[i] = ppins[i];   //softhack007 fix for potential array out-of-bounds access
   }