Tests: adjusted cache validity time in proxy_cache_use_stale.t.

proxy_cache_use_stale.t

diff --git a/proxy_cache_use_stale.t b/proxy_cache_use_stale.t
index dd7c3d8..c052093 100644
--- a/proxy_cache_use_stale.t
+++ b/proxy_cache_use_stale.t
@@ -146,10 +146,10 @@
 	'stale-while-revalidate');
 like(http_get('/t2.html'), qr/HIT/, 's-w-r - cached');
 
-get('/tt.html', 'max-age=1, stale-if-error=2');
+get('/tt.html', 'max-age=1, stale-if-error=3');
 get('/t3.html', 'max-age=1, stale-while-revalidate=2');
-get('/t4.html', 'max-age=1, stale-while-revalidate=2');
-get('/t5.html', 'max-age=1, stale-while-revalidate=2');
+get('/t4.html', 'max-age=1, stale-while-revalidate=3');
+get('/t5.html', 'max-age=1, stale-while-revalidate=3');
 get('/t6.html', 'max-age=1, stale-while-revalidate=4');
 get('/t7.html', 'max-age=1, stale-while-revalidate=10');
 http_get('/ssi.html');