Update relevancy of tests

Regression/bz299951-sendmail-does-not-return-proper-status-when-free-space-low/main.fmf

@@ -17,7 +17,7 @@ duration: 15m
 enabled: true
 link:
   - relates: https://bugzilla.redhat.com/show_bug.cgi?id=299951
-adjust:
+adjust+:
   - enabled: false
     when: distro < rhel-4, rhel-6
     continue: false

Regression/bz449391-sendmail-allows-external-mail-with-from-address-user-at-localhost-localdomain/main.fmf

@@ -55,7 +55,7 @@ tag:
   - notip
 link:
   - relates: https://bugzilla.redhat.com/show_bug.cgi?id=449391
-adjust:
+adjust+:
   - enabled: false
     when: distro < rhel-5
     continue: false

Regression/bz494408-Sendmail-should-provide-MTA/main.fmf

@@ -60,7 +60,7 @@ tag:
   - tip_destructive_el8
 link:
   - relates: https://bugzilla.redhat.com/show_bug.cgi?id=494408
-adjust:
+adjust+:
   - enabled: false
     when: distro < rhel-5
     continue: false

Regression/bz605191-config-file-in-usr-lib-usr-lib64/main.fmf

@@ -14,7 +14,7 @@ tag:
 tier: '2'
 link:
   - relates: https://bugzilla.redhat.com/show_bug.cgi?id=605191
-adjust:
+adjust+:
   - enabled: false
     when: distro < rhel-8
     continue: false

Regression/makemap-in-alternatives/main.fmf

@@ -16,7 +16,7 @@ tag:
 tier: '1'
 link:
   - relates: https://bugzilla.redhat.com/show_bug.cgi?id=1225891
-adjust:
+adjust+:
   - enabled: false
     when: distro ~< rhel-7.4
     continue: false

Regression/test-presence-statusfiles/main.fmf

@@ -13,7 +13,7 @@ duration: 5m
 enabled: true
 link:
   - relates: https://bugzilla.redhat.com/show_bug.cgi?id=890585
-adjust:
+adjust+:
   - enabled: false
     when: distro < rhel-7.4
     continue: false