Update attribution

project.xml

@@ -3,7 +3,7 @@
 <Map srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over" background-color="#fff8f0" background-image="img/noise.png">
 
 <Parameters>
-  <Parameter name="attribution"><![CDATA[<a href='https://www.mapbox.com/about/maps/' target='_blank'>&copy; Mapbox &copy; OpenStreetMap</a> <a class='mapbox-improve-map' href='https://www.mapbox.com/map-feedback/' target='_blank'>Improve this map</a>]]></Parameter>
+  <Parameter name="attribution"><![CDATA[<a href='https://www.mapbox.com/about/maps/' target='_blank'>&copy; Mapbox</a> <a href='https://openstreetmap.org/about/' target='_blank'>&copy; OpenStreetMap</a> <a class='mapbox-improve-map' href='https://www.mapbox.com/map-feedback/' target='_blank'>Improve this map</a>]]></Parameter>
   <Parameter name="bounds">-180,-85.0511,180,85.0511</Parameter>
   <Parameter name="center">-82.9688,16.8466,4</Parameter>
   <Parameter name="format">png8:m=h:c=192</Parameter>