[proc-exit-listener]: ignore blank lines

make proc-exit-listener more rebust

Signed-off-by: Guohan Lu <lguohan@gmail.com>

files/scripts/supervisor-proc-exit-listener

@@ -2,6 +2,7 @@
 
 import getopt
 import os
+import re
 import select
 import signal
 import sys
@@ -40,6 +41,9 @@ def get_critical_group_and_process_list():
 
     with open(CRITICAL_PROCESSES_FILE, 'r') as file:
         for line in file:
+            # ignore blank lines
+            if re.match(r"^\s*$", line)
+                continue
             line_info = line.strip(' \n').split(':')
             if len(line_info) != 2:
                 syslog.syslog(syslog.LOG_ERR,