I think this is causing some of them to be non-translatable too; mostly the multi-line strings.
../src/Widgets/Proxy/ProxyConfigurationPage.vala:245: warning: unterminated string constant
../src/Widgets/Proxy/ProxyConfigurationPage.vala:246: warning: unterminated string constant
../src/Widgets/Proxy/ProxyConfigurationPage.vala:271: warning: '}' found where ')' was expected
../src/Widgets/Proxy/ProxyConfigurationPage.vala:272: warning: '}' found where ')' was expected
../src/Widgets/Proxy/ProxyConfigurationPage.vala:273: warning: '}' found where ')' was expected
../src/Plug.vala:81: warning: unterminated string constant
../src/Plug.vala:84: warning: unterminated string constant
../src/Plug.vala:87: warning: unterminated string constant
../src/Plug.vala:88: warning: unterminated string constant
../src/Plug.vala:110: warning: '}' found where ')' was expected
../src/Plug.vala:173: warning: '}' found where ')' was expected
../src/Plug.vala:211: warning: '}' found where ')' was expected