fix(helper): fix bad warning message on unknown cli

[hanxiao]

fix #3172

[codecov]

Codecov Report

Merging #3237 (bb0dcb8) into master (fcf17a9) will decrease coverage by 1.47%.
The diff coverage is 91.17%.

@@            Coverage Diff             @@
##           master    #3237      +/-   ##
==========================================
- Coverage   90.49%   89.01%   -1.48%     
==========================================
  Files         148      148              
  Lines       10347    10372      +25     
==========================================
- Hits         9363     9233     -130     
- Misses        984     1139     +155     

Flag	Coverage Δ
daemon	44.22% <70.58%> (+1.37%)	⬆️
jina	88.83% <91.17%> (-1.65%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
jina/parsers/__init__.py	97.82% <ø> (ø)
jina/parsers/helper.py	45.52% <0.00%> (ø)
jina/parsers/deprecated.py	83.33% <50.00%> (-16.67%)	⬇️
jina/flow/base.py	78.12% <100.00%> (-11.10%)	⬇️
jina/helper.py	80.82% <100.00%> (+0.67%)	⬆️
jina/jaml/parsers/flow/v1.py	49.01% <0.00%> (-45.10%)	⬇️
jina/clients/__init__.py	86.20% <0.00%> (-13.80%)	⬇️
jina/peapods/runtimes/grpc/__init__.py	81.11% <0.00%> (-13.29%)	⬇️
jina/peapods/runtimes/gateway/grpc/__init__.py	92.10% <0.00%> (-7.90%)	⬇️
... and 16 more

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[github-actions]

Latency summary

Current PR yields:

• 🐢🐢 index QPS at 1415, delta to last 2 avg.: -9%
• 😶 query QPS at 38, delta to last 2 avg.: -4%
• 😶 dam extend QPS at 48564, delta to last 2 avg.: -22%
• 😶 avg flow time within 1.6333 seconds, delta to last 2 avg.: +28%
• 🐎🐎🐎🐎 import jina within 0.3723 seconds, delta to last 2 avg.: +12%

Breakdown

Version	Index QPS	Query QPS	DAM Extend QPS	Avg Flow Time (s)	Import Time (s)
current	1415	38	48564	1.6333	0.3723
2.0.19	1594	46	64333	1.3348	0.3327
2.0.18	1523	32	60582	1.2151	0.3275

Backed by latency-tracking. Further commits will update this comment.