fix segfault when geo range replaces starting part of another range

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 5535eb2..bd6499e 100644
--- a/src/http/modules/ngx_http_geo_module.c
+++ b/src/http/modules/ngx_http_geo_module.c
@@ -636,8 +636,8 @@
 
                 range = a->elts;
 
-                ngx_memcpy(&range[i + 2], &range[i + 1],
-                           (a->nelts - 2 - i) * sizeof(ngx_http_geo_range_t));
+                ngx_memcpy(&range[i + 1], &range[i],
+                           (a->nelts - 1 - i) * sizeof(ngx_http_geo_range_t));
 
                 range[i + 1].start = (u_short) (e + 1);