fix(goi18n): could not extract constant message id

[ksegun]

If you specified a constant for message id e.g

package main

import "github.com/nicksnyder/go-i18n/v2/i18n"

const constID = "ConstantID"
			
var m = &i18n.Message{
    ID: constID,
    Other: "ID is a constant",
}

goi18n extract failed with failed to marshal en strings to toml: toml: Key '' is not a valid table name. Key names cannot be empty.

[codecov]

Codecov Report

Merging #202 into master will decrease coverage by 0.04%.
The diff coverage is 75%.

@@            Coverage Diff             @@
##           master     #202      +/-   ##
==========================================
- Coverage    82.9%   82.85%   -0.05%     
==========================================
  Files          14       14              
  Lines        1293     1301       +8     
==========================================
+ Hits         1072     1078       +6     
- Misses        158      159       +1     
- Partials       63       64       +1

Impacted Files	Coverage Δ
v2/goi18n/extract_command.go	69.31% <75%> (+0.27%)	⬆️

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[nicksnyder]

Thanks for the contribution!

[ozankasikci]

Having this same problem. Please release a new version including this fix.

[nicksnyder]

2.0.3 is released