PLT-1316/PLT-3280 Change client-side max file size limit (#3354)

* Change client-side max file size limit

It now relies on the value set in config.json.
Re-enable and tweak the max file size setting in system console.

* Update file upload error message

webapp/components/file_upload.jsx

@@ -44,6 +44,7 @@ class FileUpload extends React.Component {
         this.keyUpload = this.keyUpload.bind(this);
 
         this.state = {
+            maxFileSize: global.window.mm_config.MaxFileSize,
             requests: {}
         };
     }
@@ -75,7 +76,7 @@ class FileUpload extends React.Component {
         const tooLargeFiles = [];
 
         for (let i = 0; i < files.length && numUploads < uploadsRemaining; i++) {
-            if (files[i].size > Constants.MAX_FILE_SIZE) {
+            if (files[i].size > this.state.maxFileSize) {
                 tooLargeFiles.push(files[i]);
                 continue;
             }
@@ -106,9 +107,9 @@ class FileUpload extends React.Component {
         } else if (tooLargeFiles.length > 1) {
             var tooLargeFilenames = tooLargeFiles.map((file) => file.name).join(', ');
 
-            this.props.onUploadError(formatMessage(holders.filesAbove, {max: (Constants.MAX_FILE_SIZE / 1000000), filenames: tooLargeFilenames}));
+            this.props.onUploadError(formatMessage(holders.filesAbove, {max: (this.state.maxFileSize / 1048576), filenames: tooLargeFilenames}));
         } else if (tooLargeFiles.length > 0) {
-            this.props.onUploadError(formatMessage(holders.fileAbove, {max: (Constants.MAX_FILE_SIZE / 1000000), filename: tooLargeFiles[0].name}));
+            this.props.onUploadError(formatMessage(holders.fileAbove, {max: (this.state.maxFileSize / 1048576), filename: tooLargeFiles[0].name}));
         }
     }