修复 maxWidth计算错误的问题

components/uni-im-img/uni-im-img.vue

@@ -48,8 +48,11 @@ import uniIm from '@/uni_modules/uni-im/sdk/index.js';
       load(e){
         // console.log('img load',e)
         this.width = e.detail.width
-        const maxWidth = uni.upx2px(parseInt(this.maxWidth))
-        // console.log('this.width',this.width)
+        // 如果以rpx为单位，转换为px
+        let maxWidth = parseInt(this.maxWidth)
+        if(this.maxWidth && this.maxWidth.indexOf('rpx') > -1){
+          maxWidth = parseInt(this.maxWidth) * uniIm.utils.getSystemInfoSync().windowWidth / 750
+        }
         // console.log('maxWidth',maxWidth)
         if(maxWidth && this.width > maxWidth){
           this.width = maxWidth + 'px'