Fix issue with test 055 on Cygwin

- stored value was overwritten probably due to compiler optimisation bug

src/markdown.cpp

@@ -265,9 +265,7 @@ static void convertStringFragment(QCString &result,const char *data,int size)
 {
   TRACE(result);
   if (size<0) size=0;
-  result.resize(size+1);
-  memcpy(result.rawData(),data,size);
-  result.at(size)='\0';
+  result = QCString(data,(uint)size);
 }
 
 /** helper function to convert presence of left and/or right alignment markers

src/qcstring.h

@@ -132,8 +132,6 @@ class QCString
     /** creates a string from \a str and copies over the first \a maxlen characters. */
     QCString( const char *str, uint maxlen ) : m_rep(str?str:"") { m_rep.resize(maxlen); }
 
-    /** replaces the contents by that of string \a s. */
-
     /** replaces the contents by that of C string \a str. */
     QCString &operator=( const char *str) { m_rep = str?str:""; return *this; }