fix: do not generate xerror when no enum found

[sysulq]

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[codecov-commenter]

Codecov Report

Merging #704 (de61e75) into master (b05007c) will decrease coverage by 18.44%.
The diff coverage is 47.61%.

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@@             Coverage Diff             @@
##           master     #704       +/-   ##
===========================================
- Coverage   53.40%   34.97%   -18.44%     
===========================================
  Files         189      154       -35     
  Lines       10478     7960     -2518     
===========================================
- Hits         5596     2784     -2812     
- Misses       4461     4946      +485     
+ Partials      421      230      -191     

Impacted Files	Coverage Δ
proto/error/v1/error.pb.go	86.95% <ø> (ø)
proto/helloworld/v1/helloworld.pb.go	20.00% <ø> (ø)
proto/helloworld/v1/error.pb.go	47.61% <47.61%> (ø)
pkg/util/xerror/code_msg.go	0.00% <0.00%> (-100.00%)	⬇️
pkg/core/sentinel/sentinel_circuitbreaker.go	0.00% <0.00%> (-100.00%)	⬇️
pkg/util/xgo/serial.go	0.00% <0.00%> (-96.78%)	⬇️
pkg/util/xcast/cast.go	0.00% <0.00%> (-91.67%)	⬇️
pkg/util/xgo/parallel.go	0.00% <0.00%> (-86.80%)	⬇️
pkg/util/xretry/retry.go	15.38% <0.00%> (-84.62%)	⬇️
pkg/util/xstring/conv.go	0.00% <0.00%> (-84.22%)	⬇️
... and 81 more

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