Update log grammar (microsoft#204360)

Author: alexr00

extensions/log/cgmanifest.json

@@ -6,11 +6,11 @@
 				"git": {
 					"name": "vscode-logfile-highlighter",
 					"repositoryUrl": "https://github.com/emilast/vscode-logfile-highlighter",
-					"commitHash": "8acba9307254d1887ac770057767698c82d926c6"
+					"commitHash": "eb50e785c27b4b4f7dbf6c0e801c58fe91baef5d"
 				}
 			},
 			"license": "MIT",
-			"version": "2.15.0"
+			"version": "2.17.0"
 		}
 	],
 	"version": 1

extensions/log/syntaxes/log.tmLanguage.json

@@ -4,7 +4,7 @@
 		"If you want to provide a fix or improvement, please create a pull request against the original repository.",
 		"Once accepted there, we are happy to receive an update request."
 	],
-	"version": "https://github.com/emilast/vscode-logfile-highlighter/commit/8acba9307254d1887ac770057767698c82d926c6",
+	"version": "https://github.com/emilast/vscode-logfile-highlighter/commit/eb50e785c27b4b4f7dbf6c0e801c58fe91baef5d",
 	"name": "Log file",
 	"scopeName": "text.log",
 	"patterns": [
@@ -113,7 +113,7 @@
 			"name": "string.regexp, emphasis log.exceptiontype"
 		},
 		{
-			"begin": "^[\\t ]*at",
+			"begin": "^[\\t ]*at[\\t ]",
 			"end": "$",
 			"name": "string.key, emphasis log.exception"
 		},