comment typo fix

completely irrelevant historical note:

IIUC, ~20+ years ago, "slowlaris" was referring to Solaris being
percieved as "much slower than linux" (which was partly true, but
also related to the fact that linux had less mp support at the time)

bin/varnishd/http1/cache_http1_line.c

@@ -207,7 +207,7 @@ V1L_Flush(const struct worker *wrk)
 			 * was sent.
 			 *
 			 * XXX: Add a "minimum sent data per timeout
-			 * counter to prevent slowlaris attacks
+			 * counter to prevent slowloris attacks
 			*/
 
 			if (VTIM_real() - v1l->t0 > cache_param->send_timeout) {