task.py alter scheduler heartbeat

In order to reduce the amount of queries to the database, the heartbeat
can now be set in the defs.py file.

server/web2py/applications/vidjil/models/task.py

@@ -755,4 +755,5 @@ scheduler = Scheduler(db, dict(vidjil=run_vidjil,
                                compute_contamination=compute_contamination,
                                mixcr=run_mixcr,
                                none=run_copy,
-                               pre_process=run_pre_process))
+                               pre_process=run_pre_process),
+                        heartbeat=defs.HEARTBEAT)

server/web2py/applications/vidjil/modules/defs.py.sample

@@ -61,3 +61,5 @@ LOCUS = ['TRA', 'TRA+D', 'TRB', 'TRG', 'TRD', 'TRD+',
 
 # Preventu upload and run when 1% space is left in target disk
 FS_LOCK_THRESHHOLD = 1
+
+SCHEDULER_HEARTBEAT = 5