promise: do not try to read json file when it's not created yet

slapos/promise/check_apachedex_result/__init__.py

@@ -42,6 +42,8 @@ def checkApachedexResult(apachedex_path, apachedex_report_status_file, desired_t
         message = "No result found in the apdex file or the file is corrupted"
         break
 
+  if not os.path.exists(apachedex_report_status_file):
+    return 0, "ApacheDex didn't run yet!"
   with open(apachedex_report_status_file) as f:
     try:
       json_content = json.load(f)

slapos/promise/check_slow_queries_digest_result/__init__.py

@@ -53,6 +53,8 @@ def checkMariadbDigestResult(mariadbdex_path, mariadbdex_report_status_file,
         message = "No result found in the slow query digest file or the file is corrupted"
         break
 
+  if not os.path.exists(mariadbdex_report_status_file):
+    return 0, "No slow query result yet!"
   with open(mariadbdex_report_status_file) as f:
     try:
       json_content = json.load(f)