-Wself-assign warnings

[ryandesign]

This warning appears when compiling with a modern Clang compiler:

pcre.c:1338:6: warning: explicitly assigning value of variable of type 'BOOL' (aka 'int') to itself [-Wself-assign]
utf8 = utf8;               /* Stop pedantic compilers complaining */
~~~~ ^ ~~~~
pcre.c:1411:6: warning: explicitly assigning value of variable of type 'BOOL' (aka 'int') to itself [-Wself-assign]
utf8 = utf8;               /* Stop pedantic compilers complaining */
~~~~ ^ ~~~~