.clang-format: fix duplicated mapping key

New clang versions throw error like, following commit fixes that

```console
.clang-format:26:1: error: duplicated mapping key 'AllowShortIfStatementsOnASingleLine'
AllowShortIfStatementsOnASingleLine: false
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```

Signed-off-by: flouthoc <flouthoc.git@gmail.com>

.clang-format

@@ -23,12 +23,6 @@ AlwaysBreakBeforeMultilineStrings: false
 AlwaysBreakTemplateDeclarations: MultiLine
 BinPackArguments: true
 BinPackParameters: true
-AllowShortIfStatementsOnASingleLine: false
-AllowShortLoopsOnASingleLine: false
-AllowShortCaseLabelsOnASingleLine: false
-AllowShortFunctionsOnASingleLine: false
-AllowShortBlocksOnASingleLine: false
-BreakBeforeBraces: Allman
 BraceWrapping:
   AfterCaseLabel:  true
   AfterClass:      true