disable UART output for ST-Link V2 board

on ST-Link V2 USART1_TX is also the LED pin
if you still want USART1 for debugging output, remap it
USART1_TX will then be on RST pin of connector,
USART1_RX will then be on SWIM pin of connector,
remapping is not done per default since this board already has
a limited number of pin available on the connector

application.c

@@ -39,7 +39,9 @@
 /* own libraries */
 #include "global.h" // board definitions
 #include "print.h" // printing utilities
+#if !defined(STLINKV2_ALU)
 #include "uart.h" // USART utilities
+#endif
 #include "usb_cdcacm.h" // USB CDC ACM utilities
 #include "terminal.h" // handle the terminal interface
 #include "menu.h" // menu utilities
@@ -58,12 +60,16 @@ size_t putc(char c)
 	static char last_c = 0; // to remember on which character we last sent
 	if ('\n' == c) { // send carriage return (CR) + line feed (LF) newline for each LF
 		if ('\r' != last_c) { // CR has not already been sent
+#if !defined(STLINKV2_ALU)
 			uart_putchar_nonblocking('\r'); // send CR over USART
+#endif
 			usb_cdcacm_putchar('\r'); // send CR over USB
 			length++; // remember we printed 1 character
 		}
 	}
+#if !defined(STLINKV2_ALU)
 	uart_putchar_nonblocking(c); // send byte over USART
+#endif
 	usb_cdcacm_putchar(c); // send byte over USB
 	length++; // remember we printed 1 character
 	last_c = c; // remember last character
@@ -257,7 +263,9 @@ void main(void)
 #endif
 
 	board_setup(); // setup board
+#if !defined(STLINKV2_ALU)
 	uart_setup(); // setup USART (for printing)
+#endif
 	usb_cdcacm_setup(); // setup USB CDC ACM (for printing)
 	printf("\nwelcome to the CuVoodoo STM32F1 example application\n"); // print welcome message