Update width of sample colvar

1.5A is the width used in other steps in the sample data.

Author: EzryStIago

stepA_create_DBC/sample_outputs/DBC_restraint.colvars

@@ -44,7 +44,7 @@ colvar {
 harmonicwalls {
     colvars        DBC
     lowerWalls     0.0
-    upperWalls     2.5
+    upperWalls     1.5
     forceConstant  200.0
 }