Fix regex for issues in commit messages (#7444)

* Fix regex for issues in commit messages

Use same regex as markup for matching in commits.

Fixes #7438

* make fmt

models/action_test.go

@@ -155,6 +155,25 @@ func TestPushCommits_AvatarLink(t *testing.T) {
 		pushCommits.AvatarLink("nonexistent@example.com"))
 }
 
+func TestRegExp_issueReferenceKeywordsPat(t *testing.T) {
+	trueTestCases := []string{
+		"#2",
+		"[#2]",
+		"please see go-gitea/gitea#5",
+	}
+	falseTestCases := []string{
+		"kb#2",
+		"#2xy",
+	}
+
+	for _, testCase := range trueTestCases {
+		assert.True(t, issueReferenceKeywordsPat.MatchString(testCase))
+	}
+	for _, testCase := range falseTestCases {
+		assert.False(t, issueReferenceKeywordsPat.MatchString(testCase))
+	}
+}
+
 func Test_getIssueFromRef(t *testing.T) {
 	assert.NoError(t, PrepareTestDatabase())
 	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)