win32: improve way to get current tick count in tests {#187)

Thanks to vgrin for the report

tests/bandwidth-client.c

@@ -33,16 +33,11 @@ static uint32_t gettime_ms(void)
 {
     struct timeval tv;
 #if !defined(_MSC_VER)
-    gettimeofday (&tv, NULL);
+    gettimeofday(&tv, NULL);
+    return (uint32_t) tv.tv_sec * 1000 + tv.tv_usec / 1000;
 #else
-    SYSTEMTIME st;
-
-    GetLocalTime(&st);
-    tv.tv_sec = st.wSecond;
-    tv.tv_usec = st.wMilliseconds * 1000;
+    return GetTickCount();
 #endif
-
-    return (uint32_t) tv.tv_sec * 1000 + tv.tv_usec / 1000;
 }
 
 enum {