moved discard_leading_iobuf_bytes() out from conditional

mongoose.c

@@ -791,6 +791,13 @@ static int is_error(int n) {
   return n == 0 || (n < 0 && errno != EINTR && errno != EAGAIN);
 }
 
+static void discard_leading_iobuf_bytes(struct iobuf *io, int n) {
+  if (n >= 0 && n <= io->len) {
+    memmove(io->buf, io->buf + n, io->len - n);
+    io->len -= n;
+  }
+}
+
 #ifndef NO_CGI
 #ifdef _WIN32
 struct threadparam {
@@ -1184,13 +1191,6 @@ static void read_from_cgi(struct connection *conn) {
   }
 }
 
-static void discard_leading_iobuf_bytes(struct iobuf *io, int n) {
-  if (n >= 0 && n <= io->len) {
-    memmove(io->buf, io->buf + n, io->len - n);
-    io->len -= n;
-  }
-}
-
 static void forward_post_data(struct connection *conn) {
   struct iobuf *io = &conn->local_iobuf;
   int n = send(conn->endpoint.cgi_sock, io->buf, io->len, 0);