BUG/MINOR: do not allow '#' in uploaded filenames

For 2 reasons:

- it can break HAProx's config syntax
- it is not allowed by ALOHA

misc/stringutil.go

@@ -255,7 +255,7 @@ func SanitizeFilename(name string) string {
 	}
 	// leave all alphanumeric and 3 additional ones
 	// # _ -
-	reg := regexp.MustCompile(`[^a-zA-Z0-9#_\\-]+`)
+	reg := regexp.MustCompile(`[^a-zA-Z0-9_\\-]+`)
 	name = reg.ReplaceAllString(name, "_")
 
 	if ext != "" {

misc/stringutil_test.go

@@ -23,15 +23,10 @@ func TestSanitizeFilename(t *testing.T) {
 		input string
 		want  string
 	}{
-		{
-			name:  "Should preserve # and . in input",
-			input: "#4_abc.#",
-			want:  "#4_abc.#",
-		},
 		{
 			name:  "Should convert leading dots",
 			input: ".....file.map!!@#",
-			want:  "_file.map_#",
+			want:  "_file.map_",
 		},
 		{
 			name:  "Should convert hidden files",
@@ -46,7 +41,7 @@ func TestSanitizeFilename(t *testing.T) {
 		{
 			name:  "Should sanitize input correctly",
 			input: "#1_?a;b/c!&?",
-			want:  "#1__a_b_c_",
+			want:  "_1__a_b_c_",
 		},
 		{
 			name:  "Should return same input when name doesn't contain regex characters",