When changing the font, reset the selection, fixes a crash during pinching, as we change the font size, hence changing the buffers

Sources/SwiftTerm/Mac/MacTerminalView.swift

@@ -120,6 +120,7 @@ open class TerminalView: NSView, NSTextInputClient, NSUserInterfaceValidations {
         set {
             fontSet = FontSet (font: newValue)
             resetFont()
+            selectNone()
         }
     }
     

Sources/SwiftTerm/iOS/iOSTerminalView.swift

@@ -136,7 +136,8 @@ open class TerminalView: UIScrollView, UITextInputTraits, UIKeyInput, UIScrollVi
         }
         set {
             fontSet = FontSet (font: newValue)
-            resetFont();
+            resetFont()
+            selectNone()
             fullBufferUpdate(terminal: terminal)
         }
     }