Add parenthesis in boolean expression

This fixes a compiler warning:

    scanutils.cpp:444:32: warning:
        '&&' within '||' [-Wlogical-op-parentheses]

Signed-off-by: Stefan Weil <sw@weilnetz.de>

src/ccutil/scanutils.cpp

@@ -441,7 +441,7 @@ static int tvfscanf(FILE* stream, const char *format, va_list ap) {
               unsigned length = 0;
               while (width--) {
                 q = fgetc(stream);
-                if (isascii(q) && isspace(q) || q <= 0) {
+                if ((isascii(q) && isspace(q)) || (q <= 0)) {
                   ungetc(q, stream);
                   break;
                 }