Fixes #2939 issue with placeholder color

src/definitions/elements/input.less

@@ -155,15 +155,15 @@
   box-shadow: @focusBoxShadow;
 }
 .ui.input.focus input::-webkit-input-placeholder,
-.ui.input input:focus input::-webkit-input-placeholder {
+.ui.input input:focus::-webkit-input-placeholder {
   color: @placeholderFocusColor;
 }
 .ui.input.focus input::-moz-placeholder,
-.ui.input input:focus input::-moz-placeholder {
+.ui.input input:focus::-moz-placeholder {
   color: @placeholderFocusColor;
 }
 .ui.input.focus input::-ms-input-placeholder,
-.ui.input input:focus input::-ms-input-placeholder {
+.ui.input input:focus::-ms-input-placeholder {
   color: @placeholderFocusColor;
 }