ExternalLoginForm: improve mobile text input

app/soapbox/features/external_login/components/external_login_form.js

@@ -53,7 +53,7 @@ class ExternalLoginForm extends ImmutablePureComponent {
     }
 
     return (
-      <SimpleForm onSubmit={this.handleSubmit}>
+      <SimpleForm onSubmit={this.handleSubmit} className='external-login'>
         <fieldset disabled={isLoading}>
           <FieldsGroup>
             <TextInput
@@ -63,6 +63,8 @@ class ExternalLoginForm extends ImmutablePureComponent {
               value={this.state.host}
               onChange={this.handleHostChange}
               autoComplete='off'
+              autoCorrect='off'
+              autoCapitalize='off'
               required
             />
           </FieldsGroup>

app/soapbox/features/forms/index.js

@@ -126,6 +126,7 @@ export class SimpleForm extends ImmutablePureComponent {
 
   static propTypes = {
     children: PropTypes.node,
+    className: PropTypes.string,
   };
 
   static defaultProps = {
@@ -139,9 +140,14 @@ export class SimpleForm extends ImmutablePureComponent {
   }
 
   render() {
-    const { children, onSubmit, ...props } = this.props;
+    const { className, children, onSubmit, ...props } = this.props;
     return (
-      <form className='simple_form' method='post' onSubmit={this.onSubmit} {...props}>
+      <form
+        className={classNames('simple_form', className)}
+        method='post'
+        onSubmit={this.onSubmit}
+        {...props}
+      >
         {children}
       </form>
     );