Fix: Left-align the submit button on each card for pdf operation (#1897)

src/main/resources/templates/security/remove-cert-sign.html

@@ -21,7 +21,7 @@
                   <label th:text="#{removeCertSign.selectPDF}"></label>
                   <div th:replace="~{fragments/common :: fileSelector(name='fileInput', multipleInputsForSingleRequest=false, accept='application/pdf')}"></div>
                 </div>
-                <div class="mb-3 text-center">
+                <div class="mb-3 text-left">
                   <button type="submit" id="submitBtn" class="btn btn-primary" th:text="#{removeCertSign.submit}"></button>
                 </div>
               </form>