display version as `x.y.z deb-1234` instead of `x.y.z ppa-1234`

dist/linux/debian/rules

@@ -42,7 +42,7 @@ override_dh_auto_build:
 		--java-options "-Dcryptomator.ipcSocketPath=\"~/.config/Cryptomator/ipc.socket\"" \
 		--java-options "-Dcryptomator.mountPointsDir=\"~/.local/share/Cryptomator/mnt\"" \
 		--java-options "-Dcryptomator.showTrayIcon=false" \
-		--java-options "-Dcryptomator.buildNumber=\"ppa-${REVISION_NUM}\"" \
+		--java-options "-Dcryptomator.buildNumber=\"deb-${REVISION_NUM}\"" \
 		--java-options "-Dcryptomator.appVersion=\"${SEMVER_STR}\"" \
 		--app-version "${VERSION_NUM}.${REVISION_NUM}" \
 		--resource-dir resources \