Fix segfault in netledPi

Device names in Raspbian Stretch can apparently be longer than 8 characters, causing a segmentation fault because the array that holds them is too short. Increased the array to 32 chars.
https://github.com/RagnarJensen/PiLEDlights/issues/1#event-1252022972

netledPi.c

@@ -80,7 +80,7 @@ int activity(FILE *netdevices) {
         int found_inpackets, found_outpackets;
         int result;
         char *ptr;
-        char device[8];
+        char device[32];
 
         /* Go to the beginning of the netdevices file */
         result = TEMP_FAILURE_RETRY(fseek(netdevices, 0L, SEEK_SET));