Remove previously removed fn proto from header

Author: airween

src/utils/string.h

@@ -73,7 +73,6 @@ void replaceAll(std::string *str, const std::string& from,
     const std::string& to);
 std::string removeWhiteSpacesIfNeeded(std::string a);
 std::string parserSanitizer(std::string a);
-std::string log_escape_hex(std::string s);
 
 unsigned char x2c(unsigned char *what);
 unsigned char xsingle2c(unsigned char *what);