function_body_length error value in configuration file not detected if no warning provided

[gchiacchio]

New Issue Checklist

• Updated SwiftLint to the latest version
• I searched for existing GitHub issues

Describe the bug

A clear and concise description of what the bug is.

Complete output when running SwiftLint, including the stack trace and command used

$ swiftlint lint

Environment

• SwiftLint version (run swiftlint version to be sure)?

swiftlint --version
0.50.3

• Installation method used (Homebrew, CocoaPods, building from source, etc)?
  Homebrew

• Paste your configuration file:

# insert yaml contents here
function_body_length:
    error: 4

• Are you using nested configurations?
  If so, paste their relative paths and respective contents.
• Which Xcode version are you using (check xcodebuild -version)?

Xcode 13.3.1
Build version 13E500a

• Do you have a sample that shows the issue? Run echo "[string here]" | swiftlint lint --no-cache --use-stdin --enable-all-rules
  to quickly test if your example is really demonstrating the issue. If your example is more
  complex, you can use swiftlint lint --path [file here] --no-cache --enable-all-rules.

THIS IS NOT TRIGGERING function_body_length (IT SHOULD)

echo "// Test
func test() {
    print("1")
    print("2")
    print("3")
    print("4")
    print("5")
}
" | swiftlint lint --no-cache --use-stdin

<nopath>:9:1: error: Trailing Newline Violation: Files should have a single trailing newline. (trailing_newline)
Done linting! Found 1 violation, 1 serious in 1 file.

NOW IF I ADD A warning LINE, IT WORKS

# insert yaml contents here
function_body_length:
    warning: 4
    error: 4

echo "// Test
func test() {
    print("1")
    print("2")
    print("3")
    print("4")
    print("5")
}
" | swiftlint lint --no-cache --use-stdin

<nopath>:2:6: error: Function Body Length Violation: Function body should span 4 lines or less excluding comments and whitespace: currently spans 5 lines (function_body_length)
<nopath>:9:1: error: Trailing Newline Violation: Files should have a single trailing newline. (trailing_newline)
Done linting! Found 2 violations, 2 serious in 1 file.

[gchiacchio]

note it's also failing for other rules as type_body_length, haven't tested others yet