Fixes tests after clean-css 5.3.0 upgrade.

Author: jakubpawlowicz

test/fixtures/unsupported/selectors-ie7.css

@@ -2,14 +2,14 @@ p:focus{top:0}
 p:before{top:0}
 p:after{top:0}
 p:root{top:0}
-p:nth-of-type(1){top:0}
+p:first-of-type{top:0}
 p:nth-last-of-type(1){top:0}
 p:first-of-type{top:0}
 p:last-of-type{top:0}
 p:only-of-type{top:0}
 p:only-child{top:0}
 p:last-child{top:0}
-p:nth-child(1){top:0}
+p:first-child{top:0}
 p:nth-last-child(1){top:0}
 p:empty{top:0}
 p:target{top:0}

test/fixtures/unsupported/selectors-ie8.css

@@ -1,12 +1,12 @@
 p:root{top:0}
-p:nth-of-type(1){top:0}
+p:first-of-type{top:0}
 p:nth-last-of-type(1){top:0}
 p:first-of-type{top:0}
 p:last-of-type{top:0}
 p:only-of-type{top:0}
 p:only-child{top:0}
 p:last-child{top:0}
-p:nth-child(1){top:0}
+p:first-child{top:0}
 p:nth-last-child(1){top:0}
 p:empty{top:0}
 p:target{top:0}