smartinfo: set to 500ms the default refresh time

Use a default value of 500ms for SmartTools refresh period.
This also fix the coverity issue CID # 1371961.

Change-Id: I45cb7162fa38ceeb52c73da46e815595ebbb8fa9
Tuleap: #909
Reviewed-by: Stepan Salenikovich <stepan.salenikovich@savoirfairelinux.com>

src/smartools.h

@@ -43,7 +43,7 @@ class Smartools
         void process();
         std::map<std::string, std::string> information_;
         std::mutex mutexInfo_; // Protect information_ from multithreading
-        std::chrono::milliseconds refreshTimeMs_;
+        std::chrono::milliseconds refreshTimeMs_ {500};
         ThreadLoop loop_; // Has to be last member
 };
 } //ring namespace