Fix bug with STensor43 (index 77 appears twice and no index 78...)

Solver/STensor43.h

@@ -17,7 +17,7 @@ class STensor43 {
   {
     static int _index[3][3][3][3] = {{{{0,1,2},{3,4,5},{6,7,8}},{{9,10,11},{12,13,14},{15,16,17}},{{18,19,20},{21,22,23},{24,25,26}}},
                                      {{{27,28,29},{30,31,32},{33,34,35}},{{36,37,38},{39,40,41},{42,43,44}},{{45,46,47},{48,49,50},{51,52,53}}},
-                                     {{{54,55,56},{57,58,59},{60,61,62}},{{63,64,65},{66,67,68},{69,70,71}},{{72,73,74},{75,76,77},{77,79,80}}}};
+                                     {{{54,55,56},{57,58,59},{60,61,62}},{{63,64,65},{66,67,68},{69,70,71}},{{72,73,74},{75,76,77},{78,79,80}}}};
     return _index[i][j][k][l];
   }
   STensor43(const STensor43& other)