libcap: Minor fixes

[jwillikers]

Fixes for review comments after the previous merge, #15135.

Specify library name and version: lib/1.0

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• I've read the contributing guidelines.
• I've used a recent Conan client version close to the currently deployed.
• I've tried at least one configuration locally with the conan-center hook activated.

[ghost]

I detected other pull requests that are modifying libcap/all recipe:

• libcap: modernize more #15300

This message is automatically generated by https://github.com/ericLemanissier/conan-center-conflicting-prs so don't hesitate to report issues/improvements there.

[conan-center-bot]

Conan v1 pipeline

All green in build 1 (6eab87a8cde6cabf3de2d28ddca29c2b7aba55a8):

• libcap/2.45@:
  All packages built successfully! (All logs)

• libcap/2.66@:
  All packages built successfully! (All logs)

• libcap/2.50@:
  All packages built successfully! (All logs)

• libcap/2.46@:
  All packages built successfully! (All logs)

• libcap/2.62@:
  All packages built successfully! (All logs)

• libcap/2.65@:
  All packages built successfully! (All logs)

• libcap/2.57@:
  All packages built successfully! (All logs)

• libcap/2.58@:
  All packages built successfully! (All logs)

• libcap/2.48@:
  All packages built successfully! (All logs)