fix: Centering the time on date time (quasarframework#2684)

Author: codenamezjames

src/components/datetime/QDatetimePicker.mat.js

@@ -549,7 +549,7 @@ export default {
         ]))
         const content = [
           h('span', {
-            staticClass: 'col',
+            staticClass: 'col-auto',
             style: { textAlign: 'right' }
           }, [
             h('span', {
@@ -586,7 +586,7 @@ export default {
           h('span', { style: 'opacity:0.6;' }, [ ':' ]),
 
           h('span', {
-            staticClass: 'col row no-wrap items-center',
+            staticClass: 'col-auto row no-wrap items-center',
             style: { textAlign: 'left' }
           }, [
             h('span', {