Register native messaging host also when user has no admin rights

[tobiasdiez]

As of now, the installer adds an entry in the registry pointing to the JabRef executable:

jabref/jabref.install4j

Line 578 in 1d8b3aa

<string>SOFTWARE\Mozilla\NativeMessagingHosts\org.jabref.jabref</string>

Usually, this key is placed under HKEY_LOCAL_MACHINE.

jabref/jabref.install4j

Lines 580 to 585 in 1d8b3aa

	<void property="registryRoot">
	<object class="java.lang.Enum" method="valueOf">
	<class>com.install4j.api.windows.RegistryRoot</class>
	<string>HKEY_LOCAL_MACHINE</string>
	</object>
	</void>

However, if the user does not have admin rights, it should instead be placed under HKEY_CURRENT_USER.