Added check for empty or non-existant account details file

cfddns.sh

@@ -50,10 +50,14 @@ if [ -z "$accountFile" ] || [[ $accountFile == -* ]]; then
     echo -e "\e[1;31mNo file containing account details was specified."
     echo -e "\e[0;31m(-f parameter empty or missing)\e[0m"
     exit 101
+elif [ ! -s "$accountFile" ]; then
+    echo -e "\e[1;31mAccount details file is either empty or does not" \
+        "exist.\e[0m"
+    exit 102
 elif [ -z ${dnsRecords} ]; then
     echo -e "\e[1;31mNo DNS records were specified."
     echo -e "\e[0;31m(-r parameter(s) empty or missing)\e[0m"
-    exit 102
+    exit 103
 fi