fix: set english to default langague

Refs #667

src/app/services/internationalisation.service.ts

@@ -19,6 +19,7 @@ export class I18nService extends Observable implements Observer {
     private _availableLanguages: any;
 
     /** localized messages */
+    // eslint-disable-next-line @typescript-eslint/naming-convention
     private _Messages: StringMap;
 
     /** to avoid loading language files multiple times */
@@ -60,19 +61,20 @@ export class I18nService extends Observable implements Observer {
      * @param code ISO 639-1 language code
      */
     public async setLanguage(code: string) {
-        /** excluded calculators */
         const childCalculatorType: CalculatorType[] = [
             CalculatorType.Section, CalculatorType.Structure, CalculatorType.CloisonAval, CalculatorType.YAXN,
             CalculatorType.LechaptCalmon, CalculatorType.PressureLossLaw
         ];
-
+    
         // ensure 2-letter language code
         code = code.substring(0, 2);
-        // is language supported ?
-        if (! Object.keys(this._availableLanguages).includes(code)) {
-            throw new Error(`LANGUAGE_UNSUPPORTED "${code}"`);
+    
+        // Check if the language is supported, default to English if not
+        if (!Object.keys(this._availableLanguages).includes(code)) {
+            code = "en";  // Default to English if the detected language is not supported
         }
-        // did language change ?
+    
+        // did language change?
         if (this._currentLanguage !== code) {
             this._currentLanguage = code;
             this._Messages = undefined;