AMUN, SYSTEM: Stop compiler complaining if SIGNALS is off.

Signed-off-by: Grzegorz Kowal <grzegorz@amuncode.org>

sources/amun.F90

@@ -43,7 +43,10 @@ program amun
   use random    , only : initialize_random, finalize_random
   use system    , only : initialize_system, finalize_system
   use system    , only : print_system_info, prepare_system, evolve_system
-  use system    , only : quit, nsteps, nwork
+  use system    , only : nsteps, nwork
+#ifdef SIGNALS
+  use system    , only : quit
+#endif /* SIGNALS */
   use timers    , only : initialize_timers, finalize_timers
   use timers    , only : start_timer, stop_timer, set_timer, get_timer
   use timers    , only : get_timer_total, timer_enabled, timer_description

sources/system.F90

@@ -38,9 +38,11 @@ module system
 !
   logical, save :: resumed = .false.
 
+#ifdef SIGNALS
 ! the flag indicating that the system evolution should be interrupted
 !
   integer, save :: quit    = 0
+#endif /* SIGNALS */
 
 ! the number of resumed run
 !
@@ -77,7 +79,10 @@ module system
   public :: initialize_system, finalize_system, prepare_system, evolve_system
   public :: print_system_info
   public :: resumed, name, nrun, eqsys, eos, ncells, nghosts, maxlev, nsteps
-  public :: bdims, dbnds, rngtype, tsav, nwork, quit
+  public :: bdims, dbnds, rngtype, tsav, nwork
+#ifdef SIGNALS
+  public :: quit
+#endif /* SIGNALS */
 
 !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 !
@@ -499,7 +504,10 @@ module system
       if (check_status(status /= 0)) return
 
       proceed = (nsteps <= nmax) .and. (time < tmax) .and.                     &
-                  (thrs <= trun) .and. .not. check_status(quit /= 0)
+                  (thrs <= trun)
+#ifdef SIGNALS
+      proceed = proceed .and. .not. check_status(quit /= 0)
+#endif /* SIGNALS */
 
       if (verbose) then