Update src/Microsoft.OpenApi/Properties/SRResource.resx

Author: darrelmiller

src/Microsoft.OpenApi/Properties/SRResource.resx

@@ -208,7 +208,7 @@
     <value>The path item name '{0}' MUST begin with a slash.</value>
   </data>
   <data name="Validation_PathSignatureMustBeUnique" xml:space="preserve">
-    <value>The path signature '{0}' MUST begin be unique.</value>
+    <value>The path signature '{0}' MUST be unique.</value>
   </data>
   <data name="Validation_RuleAddTwice" xml:space="preserve">
     <value>The same rule cannot be in the same rule set twice.</value>
@@ -219,4 +219,4 @@
   <data name="Validation_StringMustBeEmailAddress" xml:space="preserve">
     <value>The string '{0}' MUST be in the format of an email address.</value>
   </data>
-</root>
+</root>