fix Mei lift force

The equation was probably taken from the paper of Kurose and Komori
1999, which does not repoduce the original formula given by Mei 1992
correctly (which itself is missing a left parenthesis).
The correct formula can be looked up for example in Mei and Klausner
1994 or Loth and Dorgan 2009

src/lagrangian/cfdemParticle/subModels/forceModel/MeiLift/MeiLift.C

@@ -190,12 +190,8 @@ void MeiLift::setForce() const
                     else
                     {
                         J_star = 0.3
-                                *(     1.0
-                                      +tanh(  2.5 * log10(epsilon+0.191)  )
-                                 )
-                                *(    0.667
-                                     +tanh(  6.0 * (epsilon-0.32)  )
-                                  );
+                                 * (1.0   + tanh(2.5 * (log10(epsilon) + 0.191)))
+                                 * (0.667 + tanh(6.0 * (      epsilon  - 0.32 )));
                     }
                     Cl = J_star * 4.11 * epsilon; //multiply McLaughlin's correction to the basic Saffman model