Remove dead code

[0x6675636b796f75676974687562]

What's done:

• Dead code dropped (originally introduced as a part of Bugfix/indentation of multiline string #1364).
• See also 998d0e9.
• Original issue: Changing indentation of multiline string works incorrect #811.

[codecov]

Codecov Report

Merging #1457 (00c02f1) into master (7582190) will decrease coverage by 0.61%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #1457      +/-   ##
============================================
- Coverage     83.23%   82.62%   -0.62%     
+ Complexity     2562     2542      -20     
============================================
  Files           107      104       -3     
  Lines          7619     7471     -148     
  Branches       2103     2086      -17     
============================================
- Hits           6342     6173     -169     
- Misses          388      435      +47     
+ Partials        889      863      -26     

Flag	Coverage Δ
unittests	82.62% <ø> (-0.62%)	⬇️

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

Impacted Files	Coverage Δ
...at/ruleset/rules/chapter3/files/IndentationRule.kt	78.92% <ø> (-0.09%)	⬇️
.../kotlin/org/cqfn/diktat/plugin/maven/DiktatMojo.kt	9.09% <0.00%> (-81.82%)	⬇️
...lin/org/cqfn/diktat/plugin/maven/DiktatBaseMojo.kt	9.57% <0.00%> (-43.62%)	⬇️
...n/org/cqfn/diktat/plugin/gradle/DiktatExtension.kt
...qfn/diktat/plugin/gradle/DiktatJavaExecTaskBase.kt
...rg/cqfn/diktat/plugin/gradle/DiktatGradlePlugin.kt

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[github-actions]

JUnit Tests (macOS, EnricoMi/publish-unit-test-result-action@v1)

1 286 tests   1 270 ✔️  54s ⏱️
   158 suites       16 💤
   158 files           0 ❌

Results for commit 00c02f1.

[github-actions]

JUnit Tests (Windows, EnricoMi/publish-unit-test-result-action@v1)

1 300 tests   1 285 ✔️  2m 11s ⏱️
   159 suites       15 💤
   159 files           0 ❌

Results for commit 00c02f1.