reintroducing the fix to the single precision cosmology test - this w…

…as accidentally overwritten while addressing a merge conflict.

input/Cosmology/method_cosmology.incl

@@ -324,7 +324,7 @@
                         "is_local", "default"];
          position = [ "x", "y", "z" ];
 	 velocity = [ "vx", "vy", "vz" ];
-         constants = [ "mass", "double", 2.5581226e-5 ];
+         constants = [ "mass", "default", 2.5581226e-5 ];
          group_list = [ "is_gravitating" ];
      }
  }