formatting fix

Author: Claudio-Chies

models/airspeed/model.sdf

@@ -23,10 +23,10 @@
             <length>0.08</length>
           </cylinder>
         </geometry> <!-- Black -->
-				<material>
-					<diffuse>0.0 0.0 0.0</diffuse>
-					<specular>0.5 0.5 0.5</specular>
-				</material>
+        <material>
+          <diffuse>0.0 0.0 0.0</diffuse>
+          <specular>0.5 0.5 0.5</specular>
+        </material>
       </visual>
       <sensor name="air_speed" type="air_speed">
         <pose>0 0 0 0 0 0</pose>