Fix CTLineRef leaks (facebookarchive#1386)

Found by Clang Static Analyzer:

~/Texture/Source/ASTextNode2.mm:663:39: warning: Potential leak of an object stored into 'truncationTokenLine'
      CTLineRef truncationTokenLine = CTLineCreateWithAttributedString((CFAttributedStringRef)_truncationAttributedText);
                                      ^
~/Texture/Source/ASTextNode2.mm:666:49: warning: Potential leak of an object stored into 'additionalTruncationTokenLine'
      CTLineRef additionalTruncationTokenLine = CTLineCreateWithAttributedString((CFAttributedStringRef)_additionalTruncationMessage);
                                                ^
2 warnings generated.

Source/ASTextNode2.mm

@@ -662,10 +662,12 @@ - (BOOL)_locked_pointInsideAdditionalTruncationMessage:(CGPoint)point withLayout
 
       CTLineRef truncationTokenLine = CTLineCreateWithAttributedString((CFAttributedStringRef)_truncationAttributedText);
       CFIndex truncationTokenLineGlyphCount = truncationTokenLine ? CTLineGetGlyphCount(truncationTokenLine) : 0;
+      CFRelease(truncationTokenLine);
 
       CTLineRef additionalTruncationTokenLine = CTLineCreateWithAttributedString((CFAttributedStringRef)_additionalTruncationMessage);
       CFIndex additionalTruncationTokenLineGlyphCount = additionalTruncationTokenLine ? CTLineGetGlyphCount(additionalTruncationTokenLine) : 0;   
-
+      CFRelease(additionalTruncationTokenLine);
+
       switch (_textContainer.truncationType) {
         case ASTextTruncationTypeStart: {
           CFIndex composedTruncationTextLineGlyphCount = truncationTokenLineGlyphCount + additionalTruncationTokenLineGlyphCount;