CLEANUP: Fix typos in the http subsystem

Fix typos in code comment of the http subsystem.
diff --git a/src/http_fetch.c b/src/http_fetch.c
index a53f0fe..f8dfe33 100644
--- a/src/http_fetch.c
+++ b/src/http_fetch.c
@@ -582,8 +582,8 @@
 }
 
 /* Returns a string block containing all headers including the
- * empty line wich separes headers from the body. This is useful
- * form some headers analysis.
+ * empty line which separes headers from the body. This is useful
+ * for some headers analysis.
  */
 static int smp_fetch_hdrs(const struct arg *args, struct sample *smp, const char *kw, void *private)
 {