Avoid `TypeError` when desired_capacity is not provided to `ec2_asg` module (#5501)
Avoid `TypeError` when desired_capacity is not provided to `ec2_asg` module (#5501)

Moving the "check if min_size/max_size/desired_capacity..." code to execute BEFORE the desired_capacity code is used in the following operation:
num_new_inst_needed = desired_capacity - len(new_instances)

Otherwise the following exception occurs when desired_capacity is not specified and you're replacing instances:
    num_new_inst_needed = desired_capacity - len(new_instances)
TypeError: unsupported operand type(s) for -: 'NoneType' and 'int'

Stack Trace:

An exception occurred during task execution. The full traceback is:
Traceback (most recent call last):
  File "/var/lib/awx/.ansible/tmp/ansible-tmp-1478229985.74-62334493713074/ec2_asg", line 3044, in <module>
    main()
  File "/var/lib/awx/.ansible/tmp/ansible-tmp-1478229985.74-62334493713074/ec2_asg", line 3038, in main
    replace_changed, asg_properties=replace(connection, module)
  File "/var/lib/awx/.ansible/tmp/ansible-tmp-1478229985.74-62334493713074/ec2_asg", line 2778, in replace
    num_new_inst_needed = desired_capacity - len(new_instances)
TypeError: unsupported operand type(s) for -: 'NoneType' and 'int'

fatal: [localhost]: FAILED! => {"changed": false, "failed": true, "invocation": {"module_name": "ec2_asg"}, "module_stderr": "Traceback (most recent call last):\n  File \"/var/lib/awx/.ansible/tmp/ansible-tmp-1478229985.74-62334493713074/ec2_asg\", line 3044, in <module>\n    main()\n  File \"/var/lib/awx/.ansible/tmp/ansible-tmp-1478229985.74-62334493713074/ec2_asg\", line 3038, in main\n    replace_changed, asg_properties=replace(connection, module)\n  File \"/var/lib/awx/.ansible/tmp/ansible-tmp-1478229985.74-62334493713074/ec2_asg\", line 2778, in replace\n    num_new_inst_needed = desired_capacity - len(new_instances)\nTypeError: unsupported operand type(s) for -: 'NoneType' and 'int'\n", "module_stdout": "", "msg": "MODULE FAILURE", "parsed": false}
	to retry, use: --limit @

thaim/ansible,thaim/ansible