Stub implementation of SNMPAPI.DLL.

diff --git a/configure.ac b/configure.ac
index ed9417a..9350ee8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1305,6 +1305,7 @@
 dlls/shell32/Makefile
 dlls/shfolder/Makefile
 dlls/shlwapi/Makefile
+dlls/snmpapi/Makefile
 dlls/sti/Makefile
 dlls/tapi32/Makefile
 dlls/ttydrv/Makefile