CLEANUP: tools: drop upper case check after tolower()

In update_word_fingerprint_with_len() we convert a character to lower
case, then it's checked against lower case, upper case and digits. Let's
just drop the upper case check which cannot happen.

src/tools.c

@@ -6974,7 +6974,6 @@ void update_word_fingerprint_with_len(uint8_t *fp, struct ist word)
 		c = tolower((unsigned char)*p);
 		switch(c) {
 		case 'a'...'z': to = c - 'a' + 1; break;
-		case 'A'...'Z': to = tolower((unsigned char )c) - 'a' + 1; break;
 		case '0'...'9': to = 27; break;
 		default:        to = 28; break;
 		}