Revize c62151d4

Improved InvalidSubjectAttribute string representation and added an "except" block in CertificateController that handles this error.

src/services/certificate_service.py

@@ -57 +57 @@
         :raises InvalidCertificateAttribute: When a subject with an invalid attribute is passed
         """
         if subject.country is not None and len(subject.country) != 2:
-            raise InvalidSubjectAttribute("Country code", "Must consist of exactly 2 letters.")
+            raise InvalidSubjectAttribute("Country code", "Must consist of exactly 2 letters")
 
     # TODO usages present in method parameters but not in class diagram
     def create_root_ca(self, key: PrivateKey, subject: Subject, extensions: str = "", config: str = "",
@@ -637 +637 @@
         self.reason = reason
 
     def __str__(self):
-        return f"""Subject attribute "{self.attribute_name} is invalid (reason: {self.reason})."""
+        return f"""Subject attribute "{self.attribute_name}" is invalid (reason: {self.reason})."""