[Safari] Changing image properties produces lots of duplicated styles

[Wiktor Walc]

Steps to reproduce:

• paste the following code in source mode:

  <p>
  	<img align="left" alt="" height="168" hspace="10" src="http://a.cksource.com/c/1/inc/img/demo-little-red.jpg" width="120" /></p>
  

• switch to wysiwyg mode
• click on the image and open the image dialog
• change border, hspace, vspace
• click ok
• open image dialog again
• change border, hspace, vspace to some other values
• click ok
• result:

  <p>
  	<img alt="" src="http://a.cksource.com/c/1/inc/img/demo-little-red.jpg" style="border-color: initial; border-color: initial; border-color: initial; border-color: initial; border-top-width: 7px; border-right-width: 7px; border-bottom-width: 7px; border-left-width: 7px; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-color: initial; margin-left: 8px; margin-right: 8px; margin-top: 9px; margin-bottom: 9px; float: left; width: 120px; height: 168px; " /></p>
  

• border-color: initial; is repeated a couple of times
• the number of repeats increases every time we change border/hspace/vspace properties

This bug probably has been introduced in #4246.

[Garry Yao]

Regression of [4685].

[Garry Yao]

Fixed with [4725].