light.msstyles: Do not use transparent tab pane edges.

dlls/light.msstyles/blue_tab_pane_edge.svg

 <?xml version="1.0" encoding="UTF-8"?>
-<svg id="bitmap:48-32" width="48" height="48" version="1.1" viewBox="0 0 12.7 12.7" xmlns="http://www.w3.org/2000/svg" xmlns:cc="http://creativecommons.org/ns#" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+<svg id="bitmap:48-24" width="48" height="48" version="1.1" viewBox="0 0 12.7 12.7" xmlns="http://www.w3.org/2000/svg" xmlns:cc="http://creativecommons.org/ns#" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <metadata>
   <rdf:RDF>
    <cc:Work rdf:about="">
     <dc:format>image/svg+xml</dc:format>
     <dc:type rdf:resource="http://purl.org/dc/dcmitype/StillImage"/>
-    <dc:title/>
    </cc:Work>
   </rdf:RDF>
  </metadata>
  <g fill="#fff">
-  <rect x=".13229" y=".13229" width="12.435" height="12.171" rx=".52917" ry=".52917" stroke="#aeaeae" stroke-width=".26458"/>
-  <rect transform="matrix(1 0 .99934 .036434 0 0)" x="-341.09" y="341.31" width="5.4429" height="7.262"/>
+  <rect y="-2.2204e-16" width="12.7" height="12.7" rx=".52919" ry=".54067" stroke-linejoin="round" stroke-width=".26458"/>
+  <rect x=".13229" y=".13229" width="12.435" height="12.435" rx=".52919" ry=".54067" stroke="#aeaeae" stroke-width=".26458"/>
  </g>
 </svg>