Configure: fixed PCRE requirement check by ngx_http_rewrite_module.

The http_rewrite module cannot be selected when http is disabled.
Fixed the PCRE check condition to avoid irrelevant check failure.
This is a regression from 4d874b4d82ed.

Signed-off-by: Samuel Martin <s.martin49@gmail.com>

auto/lib/conf

diff --git a/auto/lib/conf b/auto/lib/conf
index 0b8545a..2c7af10 100644
--- a/auto/lib/conf
+++ b/auto/lib/conf
@@ -7,7 +7,7 @@
     . auto/lib/pcre/conf
 
 else
-    if [ $USE_PCRE = DISABLED -a $HTTP_REWRITE = YES ]; then
+    if [ $USE_PCRE = DISABLED -a $HTTP = YES -a $HTTP_REWRITE = YES ]; then
 
 cat << END