ENH: Removed p entry from tutorial sourcesProperties dictionary

tutorials/lagrangian/porousExplicitSourceReactingParcelFoam/filter/constant/sourcesProperties

@@ -34,7 +34,6 @@ massSource1
         {
             rho         1e-4; // kg/s
             H2O         1e-4; // kg/s
-            p           1e-4; // kg/s
         }
     }
 }