Reset options cache for generated cmake

The options for the generated cmake can be specified by the python
interface, but cannot unset. Subsequent generations of a sim
and an ocp solver lib would therefore interfere, through reused
cmake cache. This can be prevented by removing these options from
the cmake cache.

interfaces/acados_template/acados_template/c_templates_tera/CMakeLists.in.txt

@@ -397,3 +397,9 @@ if(${BUILD_ACADOS_SIM_SOLVER_LIB})
 endif(${BUILD_ACADOS_SIM_SOLVER_LIB})
 {%- endif %}
 
+# unset options for clean cmake cache on subsequent cmake runs
+unset(BUILD_ACADOS_SOLVER_LIB CACHE)
+unset(BUILD_ACADOS_OCP_SOLVER_LIB CACHE)
+unset(BUILD_EXAMPLE CACHE)
+unset(BUILD_SIM_EXAMPLE CACHE)
+unset(BUILD_ACADOS_SIM_SOLVER_LIB CACHE)