Append new lines to the lineinput string instead of doing concatenation in filefuncs.cpp

src/etc/filefuncs.cpp

@@ -8,7 +8,7 @@ string getFileContent(const string& file)
     string lineinput, fullinput;
     fileStream.open(file, ios::in);
     if (fileStream.is_open()) while (getline(fileStream, lineinput)) {
-        fullinput.append(lineinput + "\n");
+        fullinput.append(lineinput += '\n');
     } else throw Yerbacon::Exception("Could not open \"" + file + "\".");
     fileStream.close();
     return fullinput;