Fix VC warnings. Hopefully didn't break non-vc compilation.

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@10599 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/utils/time.hpp

@@ -74,7 +74,7 @@ public:
     };   // getTimeSinceEpoch
     // ------------------------------------------------------------------------
     /** In floating point seconds  */
-    static double getFloatTimeSinceEpoch(long startAt=0)
+    static float getFloatTimeSinceEpoch(long startAt=0)
     {
 #ifdef WIN32
         FILETIME ft;
@@ -99,7 +99,7 @@ public:
         struct timeval tv;
         gettimeofday(&tv, NULL);
         int millis = (tv.tv_sec - startAt)*1000 + tv.tv_usec/1000;
-        return millis/1000.0;
+        return (float)(millis/1000.0);
 #endif
     };   // getTimeSinceEpoch