Fix typo in translate() method

[codegaze]

Calling ut in Python code would escape the string due to a typo when calling the translate method.
The translate method was expecting _escape but we sent escape as a parameter.

[codecov]

Codecov Report

Merging #40 (0d2ea80) into devel (8db828e) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##            devel      #40   +/-   ##
=======================================
  Coverage   77.09%   77.09%           
=======================================
  Files          33       33           
  Lines        2667     2667           
=======================================
  Hits         2056     2056           
  Misses        611      611           

Impacted Files	Coverage Δ
transifex/native/django/utils/__init__.py	91.66% <0.00%> (ø)

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