Fix URL to nitpick-style-wemake

Apparently, the latest version (master branch)
of `wemake-python-styleguide` does not support nitpick anymore.
Therefore, we use the specific latest 0.19.2 version
of `nitpick-style-wemake.toml`.

Author: ivanovmg

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "poetry.core.masonry.api"
 
 
 [tool.nitpick]
-style = "https://raw.githubusercontent.com/wemake-services/wemake-python-styleguide/master/styles/nitpick-style-wemake.toml"
+style = "https://raw.githubusercontent.com/wemake-services/wemake-python-styleguide/0.19.2/styles/nitpick-style-wemake.toml"
 
 
 [tool.poetry]