[bug] 企业端添加到账阶段不可以输入负数，完全到账后不可添加阶段

src/views/MessagePage/PaymentVoucher.vue

@@ -75,7 +75,7 @@
       <!--    表格区域end-->
       <!--      添加阶段按钮-->
       <a-button type="primary" icon="plus" class="add-stage-btn" @click="addStage"
-                :disabled="editDisabled || Number(receivableAmount) === 0">添加阶段
+                :disabled="editDisabled || Number(receivableAmount) === 0 || receivableAmount + '' === paidAmount + ''">添加阶段
       </a-button>
 
       <!--      审核记录-->

src/views/MessagePage/modules/PaymentVoucherModal.vue

@@ -40,7 +40,7 @@
                    v-decorator="['amountReceived',validatorRules.amountReceived]"
                    :maxLength='50'
                    @blur="addZero"
-                   @change="e => e.target.value = (e.target.value.replace(/[^0-9-.]/g, '')).trim()"></a-input>
+                   @change="e => e.target.value = (e.target.value.replace(/[^0-9.]/g, '')).trim()"></a-input>
         </a-form-item>
         <a-form-item label="缴费日期" :labelCol="labelCol" :wrapperCol="wrapperCol">
           <j-date placeholder="请选择缴费日期"