fix building by msvc8 introduced in r2127
diff --git a/src/os/win32/ngx_files.h b/src/os/win32/ngx_files.h
index 294709f..2018e3f 100644
--- a/src/os/win32/ngx_files.h
+++ b/src/os/win32/ngx_files.h
@@ -123,7 +123,7 @@
                                           - 116444736000000000) / 10000000)
 
 
-#define ngx_filename_cmp(s1, s2, n)  strnicmp((char *) s1, (char *) s2, n)
+#define ngx_filename_cmp(s1, s2, n) _strnicmp((char *) s1, (char *) s2, n)
 
 
 #define ngx_getcwd(buf, size)       GetCurrentDirectory(size, buf)