fix member expression extraction if this is present in member expression

[AlexMost]

The problem:

t`${ this.user.name } hello`

was extracted to "${ undefined.user.name } hello" instead of "${ this.user.name } hello"
@Alxpy

[codecov]

Codecov Report

Merging #82 into master will increase coverage by 0.1%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master      #82     +/-   ##
=========================================
+ Coverage   96.03%   96.14%   +0.1%     
=========================================
  Files          13       13             
  Lines        1059     1063      +4     
  Branches      151      152      +1     
=========================================
+ Hits         1017     1022      +5     
+ Misses         42       41      -1

Impacted Files	Coverage Δ
src/utils.js	93.1% <100%> (+0.64%)	⬆️

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[oleksandr-kuzmenko]

nice 👍