Fix excessive warnings by MSVC 2013 64bit about size_t->int truncation

C4267: 'initializing' : conversion from 'size_t' to 'int', possible loss of data

Change-Id: I91979c685bbbd84359f7f4e19911a21a408f5d23
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/pythoneditor/tools/lexical/pythonformattoken.h

@@ -61,8 +61,8 @@ public:
 
     FormatToken(Format format, size_t position, size_t length)
         :m_format(format)
-        ,m_position(position)
-        ,m_length(length)
+        ,m_position(int(position))
+        ,m_length(int(length))
     {}
 
     inline Format format() const { return m_format; }