Prevent crashing when no market is installed

mobile/src/main/res/xml/pref_profile.xml

@@ -2,13 +2,14 @@
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
                   xmlns:app="http://schemas.android.com/apk/res/com.github.shadowsocks">
 
+    <be.mygod.preference.EditTextPreference
+            android:key="profileName"
+            android:summary="%s"
+            android:title="@string/profile_name"/>
+
     <be.mygod.preference.PreferenceCategory
             android:title="@string/proxy_cat">
 
-        <be.mygod.preference.EditTextPreference
-                android:key="profileName"
-                android:summary="%s"
-                android:title="@string/profile_name"/>
         <be.mygod.preference.EditTextPreference
                 android:key="proxy"
                 android:summary="%s"

mobile/src/main/scala/com/github/shadowsocks/ProfilesFragment.scala

@@ -358,7 +358,9 @@ final class ProfilesFragment extends ToolbarFragment with Toolbar.OnMenuItemClic
         REQUEST_SCAN_QR_CODE) catch {
         case _: ActivityNotFoundException =>
           Toast.makeText(getActivity, R.string.add_profile_scanner_not_installed, Toast.LENGTH_LONG).show()
-          startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=tw.com.quickmark")))
+          try startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=tw.com.quickmark"))) catch {
+            case exc: ActivityNotFoundException => exc.printStackTrace()
+          }
       }
       true
     case R.id.action_import =>