fix unicode escape min length

Author: msftrncs

PowerShellSyntax.tmLanguage

@@ -3821,7 +3821,7 @@
 			<array>
 				<dict>
 					<key>match</key>
-					<string>`u\{(?:(?:10)?([0-9a-fA-F]){,4}|0?\g&lt;1&gt;{1,5})}</string>
+					<string>`u\{(?:(?:10)?([0-9a-fA-F]){1,4}|0?\g&lt;1&gt;{1,5})}</string>
 					<key>name</key>
 					<string>constant.character.escape.powershell</string>
 				</dict>