Change "Donate" link to librepay.com

Fixes #788

Signed-off-by: Lukas Holecek <hluk@email.cz>

README.md

@@ -12,7 +12,7 @@ CopyQ is advanced clipboard manager with editing and scripting features.
 - [Documentation](https://copyq.readthedocs.io)
 - [Mailing List](https://groups.google.com/group/copyq)
 - [Bug Reports](https://github.com/hluk/CopyQ/issues)
-- [Donate](https://www.bountysource.com/teams/copyq)
+- [Donate](https://liberapay.com/CopyQ/)
 - [Scripting API](https://copyq.readthedocs.io/en/latest/scripting-api.html)
 
 ## Overview

shared/com.github.hluk.copyq.appdata.xml

@@ -22,7 +22,7 @@
     <url type="bugtracker">https://github.com/hluk/CopyQ/issues</url>
     <url type="help">https://copyq.readthedocs.io</url>
     <url type="faq">https://copyq.readthedocs.io/en/latest/faq.html</url>
-    <url type="donation">https://www.bountysource.com/teams/copyq</url>
+    <url type="donation">https://liberapay.com/CopyQ/</url>
     <url type="translate">https://hosted.weblate.org/engage/copyq/</url>
 
     <releases>

src/gui/aboutdialog.cpp

@@ -114,7 +114,7 @@ QString AboutDialog::aboutPage()
             + helpLink( tr("Author"), QString::fromUtf8("Lukáš Holeček"), IconUser )
             + helpLink( tr("E-mail"), helpMail("hluk@email.cz"), IconEnvelope )
             + helpLink( tr("Web"), helpUrl("https://hluk.github.io/CopyQ/"), IconHome )
-            + helpLink( tr("Donate"), helpUrl("https://www.bountysource.com/teams/copyq"), IconGift )
+            + helpLink( tr("Donate"), helpUrl("https://liberapay.com/CopyQ/"), IconGift )
             +
         "</table>"
         "</p>"