Fix error reported on Marketplace installation

see https://marketplace.eclipse.org/content/error/report/4206411

Error Message:
`Operation details`
Installable Units Reported:
`com.github.cameltooling.lsp.eclipse.client.feature.feature.group,1.0.0.201807110925`
Detailed Message:
`Cannot complete the install because one or more required items could not be found. Software being installed: Tooling for Apache Camel based on Apache Camel implementation of Language Server Protocol 1.0.0.201807110925 (com.github.cameltooling.lsp.eclipse.client.feature.feature.group 1.0.0.201807110925) Missing requirement: Apache Camel LSP Client Extensions Plugin 1.0.0.201807110925 (com.github.camel-tooling.eclipse.client 1.0.0.201807110925) requires 'bundle org.eclipse.lsp4e 0.6.0' but it could not be found Cannot satisfy dependency: From: Tooling for Apache Camel based on Apache Camel implementation of Language Server Protocol 1.0.0.201807110925 (com.github.cameltooling.lsp.eclipse.client.feature.feature.group 1.0.0.201807110925) To: com.github.camel-tooling.eclipse.client [1.0.0.201807110925]`

it seems to come when the user doesn't have lsp4e pre-installed (or in the correct version) locally. It should be possible to add some extra repository to help during installation