fix: 解决titleNView内button未设置text导致报错的问题

packages/uni-h5/package.json

 {
 	"name": "@dcloudio/uni-h5",
-	"version": "0.3.0",
+	"version": "0.3.1",
 	"description": "uni-app h5",
 	"main": "dist/index.umd.min.js",
 	"scripts": {

src/platforms/h5/components/page/pageHead.vue

@@ -6,12 +6,12 @@
       class="uni-page-head"
     >
       <div class="uni-page-head-hd">
-        <div
-          v-show="backButton"
-          class="uni-page-head-btn"
+        <div
+          v-show="backButton"
+          class="uni-page-head-btn"
           @click="_back">
-          <i
-            :style="{color:color,fontSize:'27px'}"
+          <i
+            :style="{color:color,fontSize:'27px'}"
             class="uni-btn-icon">&#xe601;</i>
         </div>
         <template v-for="(btn,index) in btns">
@@ -32,15 +32,15 @@
           </div>
         </template>
       </div>
-      <div
-        v-if="!searchInput"
+      <div
+        v-if="!searchInput"
         class="uni-page-head-bd">
         <div
           :style="{fontSize:titleSize,opacity:type==='transparent'?0:1}"
           class="uni-page-head__title"
         >
-          <i
-            v-if="loading"
+          <i
+            v-if="loading"
             class="uni-loading"/>
           {{ titleText }}
         </div>
@@ -89,8 +89,8 @@
         </template>
       </div>
     </div>
-    <div
-      v-if="type!=='transparent'"
+    <div
+      v-if="type!=='transparent'"
       class="uni-placeholder"/>
   </uni-page-head>
 </template>
@@ -371,7 +371,7 @@ export default {
             btn.fontFamily = fontFamily
           }
           btn.color = this.type === 'transparent' ? '#fff' : (btn.color || this.textColor)
-          let fontSize = btn.fontSize || (this.type === 'transparent' || btn.text.indexOf('\\u') >= 0 ? '22px' : '27px')
+          let fontSize = btn.fontSize || (this.type === 'transparent' || /\\u/.test(btn.text) ? '22px' : '27px')
           if (/\d$/.test(fontSize)) {
             fontSize += 'px'
           }