[docs] [issue18572] Remove redundant note about surrogates in string escape doc

[R. David Murray]

R. David Murray added the comment:

Python 3.2.3 (default, Jun 15 2013, 14:13:52) 
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> '\uD80C\uDC80'
'\ud80c\udc80'
>>> '\uD80C\uDC80' == '\U00013080'
False

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nosy: +r.david.murray

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