tests: Fixing compilation on 32-bit platform with gcc 4.2.1

Change-Id: Ic36ee35e3fed3f67eea6b0dbd4c7e3316c0cab26
diff --git a/tests/util/test-time.cpp b/tests/util/test-time.cpp
index b1fbc71..47454e3 100644
--- a/tests/util/test-time.cpp
+++ b/tests/util/test-time.cpp
@@ -15,7 +15,7 @@
 {
   time::system_clock::TimePoint value = time::system_clock::now();
   time::system_clock::TimePoint referenceTime =
-    time::fromUnixTimestamp(time::milliseconds(1390966967032));
+    time::fromUnixTimestamp(time::milliseconds(1390966967032LL));
 
   BOOST_CHECK_GT(value, referenceTime);