fix: Guard against null scheme in RedisStoreImplBase for relative URIs

[jsolferreira]

Summary

URI.getScheme() returns null for scheme-less URIs such as //localhost:6379.
In RedisStoreImplBase, the TLS detection line:

boolean tls = builder.tls || builder.uri.getScheme().equals("rediss");

called .equals() on that null, throwing an NPE at store construction time.

Fixed by flipping to the null-safe form:

boolean tls = builder.tls || "rediss".equals(builder.uri.getScheme());

A scheme-less URI now correctly resolves TLS to false (unless explicitly set via .tls(true)).

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Note

Low Risk
Single-line defensive null check with unchanged TLS semantics for valid redis/rediss URIs.

Overview
Fixes an NPE when constructing the Redis data store from a URI with no scheme (e.g. //localhost:6379).

TLS detection in RedisStoreImplBase used builder.uri.getScheme().equals("rediss"), which throws if getScheme() is null. It now uses "rediss".equals(builder.uri.getScheme()), so scheme-less URIs are treated as non-TLS unless builder.tls is set explicitly.

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[tanderson-ld]

Thank you for the contribution!