Geo: fixed access to already freed memory.

Previously, in "ranges" mode when all added ranges were deleted,
the ctx.high.low[i] was left pointing to a temporary array.

src/http/modules/ngx_http_geo_module.c

diff --git a/src/http/modules/ngx_http_geo_module.c b/src/http/modules/ngx_http_geo_module.c
index 9b3c6cb..53e8969 100644
--- a/src/http/modules/ngx_http_geo_module.c
+++ b/src/http/modules/ngx_http_geo_module.c
@@ -469,7 +469,12 @@
             for (i = 0; i < 0x10000; i++) {
                 a = (ngx_array_t *) ctx.high.low[i];
 
-                if (a == NULL || a->nelts == 0) {
+                if (a == NULL) {
+                    continue;
+                }
+
+                if (a->nelts == 0) {
+                    ctx.high.low[i] = NULL;
                     continue;
                 }
 

src/stream/ngx_stream_geo_module.c

diff --git a/src/stream/ngx_stream_geo_module.c b/src/stream/ngx_stream_geo_module.c
index ed1a488..32fb9c0 100644
--- a/src/stream/ngx_stream_geo_module.c
+++ b/src/stream/ngx_stream_geo_module.c
@@ -436,7 +436,12 @@
             for (i = 0; i < 0x10000; i++) {
                 a = (ngx_array_t *) ctx.high.low[i];
 
-                if (a == NULL || a->nelts == 0) {
+                if (a == NULL) {
+                    continue;
+                }
+
+                if (a->nelts == 0) {
+                    ctx.high.low[i] = NULL;
                     continue;
                 }