Fix initial scroll overflow with padding (from @joelkim)

IPython/html/static/notebook/less/outputarea.less

@@ -92,7 +92,7 @@ div.output_area pre {
 /* This class is for the output subarea inside the output_area and after
    the prompt div. */
 div.output_subarea {
-    padding: @code_padding @code_padding 0.0em @code_padding;
+    padding: @code_padding;
     .box-flex1();
 }
 

IPython/html/static/style/ipython.min.css

@@ -867,7 +867,7 @@ div.output_area pre {
 /* This class is for the output subarea inside the output_area and after
    the prompt div. */
 div.output_subarea {
-  padding: 0.4em 0.4em 0em 0.4em;
+  padding: 0.4em;
   /* Old browsers */
   -webkit-box-flex: 1;
   -moz-box-flex: 1;

IPython/html/static/style/style.min.css

@@ -9491,7 +9491,7 @@ div.output_area pre {
 /* This class is for the output subarea inside the output_area and after
    the prompt div. */
 div.output_subarea {
-  padding: 0.4em 0.4em 0em 0.4em;
+  padding: 0.4em;
   /* Old browsers */
   -webkit-box-flex: 1;
   -moz-box-flex: 1;