MERGE: get_nz can return with and without GCs

Author: aaronjridley

src/ions_bcs.cpp

@@ -30,7 +30,7 @@ bool Ions::set_bcs(Grid grid,
 
     bool didWork = true;
 
-    if (input.get_nAltsGeo() > 1) {
+    if (grid.get_nZ(false) > 1) {
         didWork = set_lower_bcs(grid, time, indices);
 
         if (didWork)