Fix inline error with travis gcc-4.8

lib/nghttp2_hd.c

@@ -114,7 +114,7 @@ static int memeq(const void *s1, const void *s2, size_t n) {
  * This function was generated by genlibtokenlookup.py.  Inspired by
  * h2o header lookup.  https://github.com/h2o/h2o
  */
-static inline int lookup_token(const uint8_t *name, size_t namelen) {
+static int lookup_token(const uint8_t *name, size_t namelen) {
   switch (namelen) {
   case 2:
     switch (name[1]) {