net/rustconn: Update to 0.12.7

• Add devel/desktop-file-utils to USES, because the program handles the MIME type application/x-rdp

ChangeLog:

• https://github.com/totoshko88/RustConn/releases/tag/v0.12.0
• https://github.com/totoshko88/RustConn/releases/tag/v0.12.1
• https://github.com/totoshko88/RustConn/releases/tag/v0.12.2
• https://github.com/totoshko88/RustConn/releases/tag/v0.12.3
• https://github.com/totoshko88/RustConn/releases/tag/v0.12.4
• https://github.com/totoshko88/RustConn/releases/tag/v0.12.5
• https://github.com/totoshko88/RustConn/releases/tag/v0.12.6
• https://github.com/totoshko88/RustConn/releases/tag/v0.12.7

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