fix: Improve login, server selection and proxy configuration (#2511)

No potentially malicious URLs referenced in markdown; added
servers stays in server selector list; the currently active server
is visible on the bottom right of smaller screens; a proxy configuration
can be provided now and works; a trailing slash in the added server
is no problem anymore, because it's removed.

FIXES: WEB-193

src/app/login/login.component.html

@@ -66,11 +66,11 @@
     -->
     <mifosx-login-form *ngIf="!resetPassword && !twoFactorAuthenticationRequired"></mifosx-login-form>
 
-    <div class="layout-row m-t-20">
+    <div class="layout-row">
       <mifosx-reset-password *ngIf="resetPassword"></mifosx-reset-password>
       <mifosx-two-factor-authentication *ngIf="twoFactorAuthenticationRequired"></mifosx-two-factor-authentication>
     </div>
-    <div class="layout-row m-t-20">
+    <div class="layout-row">
       <!-- Contact Information/Resources (hidden on smaller screens) -->
       <mat-list class="information-list align-items-center custom-horizontal-list hide-lt-lg">
         <mat-list-item