Correct usage for ap_scan_http_token (had used _get_ syntax), noted by RĂ¼diger

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1754570 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/server/protocol.c b/server/protocol.c
index 3e8b787..cef7517 100644
--- a/server/protocol.c
+++ b/server/protocol.c
@@ -945,8 +945,8 @@
                 else /* Using strict RFC7230 parsing */
                 {
                     /* Ensure valid token chars before ':' per RFC 7230 3.2.4 */
-                    if (!(value = (char *)ap_scan_http_token(last_field))
-                            || *value != ':') {
+                    value = (char *)ap_scan_http_token(last_field);
+                    if ((value > last_field) || *value != ':') {
                         r->status = HTTP_BAD_REQUEST;
                         apr_table_setn(r->notes, "error-notes",
                             apr_psprintf(r->pool,