Fix line breaks on add-ons with spaces

Created by: luishdez

Before

After

docs/assets/css/bootstrap.css

@@ -1711,6 +1711,7 @@ input[type="color"].input-small {
 .input-group-addon,
 .input-group-btn {
   width: 1%;
+  white-space: nowrap;
   vertical-align: middle;
 }
 

less/forms.less

@@ -321,6 +321,7 @@ input[type="color"] {
 .input-group-addon,
 .input-group-btn {
   width: 1%;
+  white-space: nowrap;
   vertical-align: middle; // Match the inputs
 }