fix(sand-monitor): 更新采砂区和监控设备数量显示

- 将采砂区个数从2个更新为3个
- 将监控设备个数从2个更新为3个

src/views/sand-monitor/left.vue

@@ -9,7 +9,7 @@
               <img src="@/assets/image/sand-monitor/采砂区.png" style="width: 0.38rem; height: 0.32rem" />
               <div class="item-content">
                 <span class="label">采砂区个数</span>
-                <span class="value" style="color: #4183d3">2个</span>
+                <span class="value" style="color: #4183d3">3个</span>
               </div>
             </div>
             <img src="@/assets/image/sand-monitor/icon-bg.png" style="width: 1.6rem" />
@@ -19,7 +19,7 @@
               <img src="@/assets/image/sand-monitor/监控设备.png" style="width: 0.32rem; height: 0.3rem" />
               <div class="item-content">
                 <span class="label">监控设备</span>
-                <span class="value" style="color: #fcd294">2个</span>
+                <span class="value" style="color: #fcd294">3个</span>
               </div>
             </div>
             <img src="@/assets/image/sand-monitor/icon-bg.png" style="width: 1.6rem" />