Point#to_line_protocol fails with FrozenError under RUBYOPT="--enable-frozen-string-literal

[defkode]

Steps to reproduce:

RUBYOPT="--enable-frozen-string-literal" ruby -Itest test/influxdb/point_test.rb

Expected behavior:

Should work with RUBYOPT="--enable-frozen-string-literal" enabled

Actual behavior:

raises FrozenError:

FrozenError: can't modify frozen String: ""
    lib/influxdb2/client/point.rb:120:in 'InfluxDB2::Point#to_line_protocol'

Specifications:

• Client Version: latest
• Platform: Linux/Mac