Revert "Dealing with trailing whitespaces"

The validation script from #10681 is too pedantic, and does not handle
well situations like:

```
cat <<EOF   # or <<-EOF
	Whether the leading whitespace is stripped out or not by bash
	it should still be considered as valid.
EOF
```

This reverts commit 4e65c1c319.

Signed-off-by: Tibor Vass <tibor@docker.com>

integration/fixtures/https/server-cert.pem

@@ -23,22 +23,22 @@ Certificate:
                     a8:05:32:1e:f9:95:09:14:75
                 Exponent: 65537 (0x10001)
         X509v3 extensions:
-            X509v3 Basic Constraints:
+            X509v3 Basic Constraints: 
                 CA:FALSE
-            Netscape Cert Type:
+            Netscape Cert Type: 
                 SSL Server
-            Netscape Comment:
+            Netscape Comment: 
                 Easy-RSA Generated Server Certificate
-            X509v3 Subject Key Identifier:
+            X509v3 Subject Key Identifier: 
                 14:02:FD:FD:DD:13:38:E0:71:EA:D1:BE:C0:0E:89:1A:2D:B6:19:06
-            X509v3 Authority Key Identifier:
+            X509v3 Authority Key Identifier: 
                 keyid:66:EE:C3:17:3D:3D:AB:44:01:6B:6F:B2:99:19:BD:AA:02:B5:34:FB
                 DirName:/C=US/ST=CA/L=SanFrancisco/O=Fort-Funston/OU=changeme/CN=changeme/name=changeme/emailAddress=mail@host.domain
                 serial:FD:AB:EC:6A:84:27:04:A7
 
-            X509v3 Extended Key Usage:
+            X509v3 Extended Key Usage: 
                 TLS Web Server Authentication
-            X509v3 Key Usage:
+            X509v3 Key Usage: 
                 Digital Signature, Key Encipherment
     Signature Algorithm: sha1WithRSAEncryption
          40:0f:10:39:c4:b7:0f:0d:2f:bf:d2:16:cc:8e:d3:9a:fb:8b: