style(shareDialog): remove redundant "注:" text from qrcode tip

clean up the UI text by removing the manually added "注:" prefix, since the language pack already provides the full note text

src/components/pptEasyClass/shareDialog.vue

@@ -21,7 +21,7 @@
         </el-input>
         <div class="qrcode" ref="qrCodeRef"></div>
 				<el-link class="qrcodeBtn" type="primary" @click="downloadQrCode()">{{ lang.ssDownloadQRCode }}</el-link>
-        <div class="qrcodeTip">注:{{ lang.ssLinkNote }}</div>
+        <div class="qrcodeTip">{{ lang.ssLinkNote }}</div>
       </div>
       <!-- <span slot="footer" class="shareFooter">
         <el-button @click="close()">{{ lang.ssCancelBtn }}</el-button>