Fixup ridefilecache best decimals

.. forgot that the values are converted to
   zero decimals when stored.

This fixes strange results when filtering by
wpk or speed, or any series that has decimal
places.

src/RideFileCache.cpp

@@ -1244,7 +1244,8 @@ RideFileCache::best(Context *context, QString filename, RideFile::SeriesType ser
         inFile.readRawData((char*)&readhere, sizeof(float));
         cacheFile.close();
 
-        return readhere; // will convert to double
+        double divisor = pow(10, decimalsFor(series)); // ? 10 : 1;
+        return readhere / divisor; // will convert to double
     }
 
     return 0;