chore: fix a typo in Bootstrap class name

No user visiable changes.

Should be in the following commits:
- f27faf0 (HideImageForm.js)
- 6fcb730 ("Replace image" button)
- 27d1204 ("Add image" button)

Fix #1724

[skip ci]

src/main/frontend/src/components/HideImageForm.js

@@ -135,7 +135,7 @@ class HideImageFormView extends React.PureComponent {
 						</div>
 					</div>
 
-					<div className="form-group from-group-sm">
+					<div className="form-group form-group-sm">
 						<div className="col-sm-offset-3 col-sm-8">
 							<button
 								type="submit"

src/main/webapp/WEB-INF/views/series/info.html

@@ -131,7 +131,7 @@
 												/*/-->
 											</div>
 										</div>
-										<div class="form-group from-group-sm">
+										<div class="form-group form-group-sm">
 											<div class="col-sm-offset-3 col-sm-8">
 												<input type="submit" class="btn btn-primary btn-sm" value="Add image" th:value="#{t_add_image}" />
 											</div>
@@ -162,7 +162,7 @@
 												/*/-->
 											</div>
 										</div>
-										<div class="form-group from-group-sm" th:if="${allowReplacingImages}">
+										<div class="form-group form-group-sm" th:if="${allowReplacingImages}">
 											<div class="col-sm-offset-3 col-sm-8">
 												<!--/* @todo #1303 Replace image form: arrange submit buttons in a one line  */-->
 												<input type="submit" class="btn btn-default btn-sm" name="replaceImage" value="Replace image" th:value="#{t_replace_image}" />