remove setting timeout proc to null #2591

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/shell/datalog_frontend.cpp

@@ -257,7 +257,6 @@ unsigned read_datalog(char const * file) {
             true);
         return ERR_MEMOUT;
     }
-    register_on_timeout_proc(nullptr);
     return 0;
 }
 

src/shell/lp_frontend.cpp

@@ -91,7 +91,6 @@ void run_solver(lp_params & params, char const * mps_file_name) {
     }
 
     display_statistics();
-    register_on_timeout_proc(nullptr);
     g_solver = nullptr;
     delete solver;
 }

src/shell/opt_frontend.cpp

@@ -127,7 +127,6 @@ static unsigned parse_opt(std::istream& in, opt_format f) {
         std::cerr << ex.msg() << "\n";
     }
     display_statistics();
-    register_on_timeout_proc(nullptr);
     g_opt = nullptr;
     return 0;
 }