Description of problem:
Newer versions need additional selinux rules to work. 

Version-Release number of selected component (if applicable):
selinux-policy-targeted-3.13.1-102.el7_3.16.noarch


audit:
type=AVC msg=audit(1502196618.804:2350): avc:  denied  { sys_nice } for  pid=50312 comm="stunnel" capability=23  scontext=system_u:system_r:stunnel_t:s0 tcontext=system_u:system_r:stunnel_t:s0 tclass=capability
type=AVC msg=audit(1502196618.804:2350): avc:  denied  { setsched } for  pid=50312 comm="stunnel" scontext=system_u:system_r:stunnel_t:s0 tcontext=system_u:system_r:stunnel_t:s0 tclass=process



Additional rule:
require {
        type stunnel_t;
        class capability { dac_override dac_read_search sys_nice };
        class process setsched;
}

#============= stunnel_t ==============
allow stunnel_t self:capability { dac_override dac_read_search sys_nice };
allow stunnel_t self:process setsched;