V2 fixed outdated and hardcoded value in stake rpl

[thomaspanf]

This PR fixes a message in stake-rpl that was outdated and hardcoded

Old:

Are you sure you want to stake 543.482558 RPL? You will not be able to unstake this RPL until you exit your validators and close your minipools, or reach over 100% collateral! [y/n]

New:

Are you sure you want to stake 543.482558 RPL? You will not be able to unstake this RPL until you exit your validators and close your minipools, or reach 1086.965117 staked RPL (60% of bonded eth)! [y/n]

[github-actions]

Coverage Report

[github-actions]

Merging this branch will not change overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/rocket-pool/smartnode/v2/rocketpool-cli/commands/node	0.01% (ø)
github.com/rocket-pool/smartnode/v2/rocketpool-daemon/api/node	0.00% (ø)
github.com/rocket-pool/smartnode/v2/shared/types/api	0.00% (ø)

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Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/rocket-pool/smartnode/v2/rocketpool-cli/commands/node/stake-rpl.go	0.00% (ø)	520	0	520
github.com/rocket-pool/smartnode/v2/rocketpool-daemon/api/node/stake-rpl.go	0.00% (ø)	295 (+54)	0	295 (+54)
github.com/rocket-pool/smartnode/v2/shared/types/api/node.go	0.00% (ø)	184	0	184

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.