XLFormTextView textChanged: fires excessively

[drifkind]

Every instance of XLFormTextView gets notified when any text view changes. Fix:

--- a/XLForm/XL/Helpers/Views/XLFormTextView.m
+++ b/XLForm/XL/Helpers/Views/XLFormTextView.m
@@ -40,7 +40,7 @@ - (instancetype)initWithFrame:(CGRect)frame
         self.contentInset = UIEdgeInsetsMake(0, -4, 0, 0);
         [self setPlaceholder:@""];
         [self setPlaceholderColor:[UIColor colorWithRed:.78 green:.78 blue:.80 alpha:1.0]];
-        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textChanged:) name:UITextViewTextDidChangeNotification object:nil];
+        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textChanged:) name:UITextViewTextDidChangeNotification object:self];
     }
     return self;
 }