Remove an extra 'i' char

Author: raxbg

lib/Sabberworm/CSS/Property/KeyframeSelector.php

@@ -16,7 +16,7 @@ class KeyframeSelector extends Selector {
 			(?:([\'"]).*?(?<!\\\\)\2)?                              # a quoted text like [id="example"]
 		)*
 	)|
-	(\d+%i)                                                         # keyframe animation progress percentage (e.g. 50%)
+	(\d+%)                                                          # keyframe animation progress percentage (e.g. 50%)
 	$
 	/ux';