Configure: initialization of NGX_ADDON_SRCS.
diff --git a/auto/options b/auto/options
index 0b21def..110141d 100644
--- a/auto/options
+++ b/auto/options
@@ -134,6 +134,7 @@
 DYNAMIC_MODULES=
 
 NGX_ADDONS=
+NGX_ADDON_SRCS=
 NGX_ADDON_DEPS=
 DYNAMIC_ADDONS=